Is Buddhist practice a form of suicide? I don't presume to understand Buddhism very well, but I'm trying to increase my understanding of the Dhamma, so please don't take what I write the wrong way. I'm not being disrespectful, because even the Buddha praised Sariputta for his unwillingness to accept teachings on faith alone, but rather from his own personal experience and understanding.

I sometimes feel like Buddhist practice is a slow form of suicide. Gradually, all interest in life, the world, family, friends, romantic interests, sense pleasures and even love itself needs to be ultimately abandoned and renounced. Nibbana is considered to be the ultimate freedom and highest happiness because it ends all suffering by extinguishing the mind from all forms of existence forever. This is denied as being annihilation because its argued that since there was never a true self to begin with, there was nothing to be annihilated. Nevertheless, we still experience a subjective experience of a self, otherwise, there would be no point in practicing the Eightfold Path. 

Because only a deluded (unenlightened) mind could have any motivation to extinguish itself, craving Nibbana seems very much like a strong aversion to existence. Anyone who tries to logically extrapolate this to justify suicide as a means to accomplish the same result is denied because its argued that a desire for annihilation (via suicide) creates more bad karma which causes rebirth. Yet, desiring annihilation via the Eightfold Path is somehow exempt from this. If someone wants to remain in Samsara forever, it's very easy to do, no effort is required. But if someone craves to permanently self-destruct via Nibbana, they must be highly motivated and diligent in their efforts, perhaps spanning many lifetimes. Some people even abandon all worldly life to become monastics to accomplish this in the fastest and most direct manner possible. Thus, it seems that to remain in Samsara requires much less desire and effort than to seek one's own annihilation via the Eightfold Path.

Again, I realize people will argue that you can't annihilate what doesn't truly exist, but this existence which all sentient beings experience as subjective reality is all a deluded mind can ever know, so seeking to extinguish that reality seems like a desire for non-existence which is supposed to create more bad karma and rebirth. I honestly struggle to follow the logic of this.
I don't presume to understand Buddhism very well


The above self-awareness is wise. 


  I sometimes feel like Buddhist practice is a slow form of suicide. 


Its not. 'Dhamma' means that which 'supports' life therefore dhamma cannot be suicide. 


  Gradually, all interest in life, the world, family, friends, romantic interests, sense pleasures and even love itself needs to be ultimately abandoned and renounced. 


Yes. Buddhism says to attain the higher pleasures of jhana &amp; Nibbana, worldly pleasures must be abandoned. 


  Nibbana is considered to be the ultimate freedom and highest happiness because it ends all suffering by extinguishing the mind from all forms of existence forever. 


No. Nibbana is the here-&amp;-now freedom from the disturbing emotions of greed, hatred &amp; delusion. As for the word "existence" ("bhava"), it means "ego-existence", which is the root of suffering. 


  This is denied as being annihilation because its argued that since there was never a true self to begin with, there was nothing to be annihilated. 


Actually, the Buddha did say in one sutta he annihilates greed, hatred &amp; self-delusion. But this does not involve suicide. 


  Nevertheless, we still experience a subjective experience of a self, otherwise, there would be no point in practicing the Eightfold Path.


It is the mind that suffers (when it ignorantly creates self-view) rather than a self that suffers. The end of suffering in Buddhism is called freedom of mind (ceto-vimutti) rather than freedom of self. 


  Because only a deluded (unenlightened) mind could have any motivation to extinguish itself


Nibbana is not the extinguishing of mind. Nibbana is the extinguishing of greed, hatred &amp; delusion. 


  Nibbana seems very much like a strong aversion to existence. 


No. 


  Anyone who tries to logically extrapolate this to justify suicide as a means to accomplish the same result is denied because its argued that a desire for annihilation (via suicide) creates more bad karma which causes rebirth.


Nibbana has no correlation to suicide. Nibbana is the freedom from the pain that motivates suicide. 


  Yet, desiring annihilation via the Eightfold Path is somehow exempt from this.


The idea that Nibbana is ending of mind is wrong understanding of Buddhism. 


  If someone wants to remain in Samsara forever, it's very easy to do, no effort is required. 


Samsara means the continuous attaching to things as self. Refer to SN 22.99. 


  But if someone craves to permanently self-destruct via Nibbana 


Craving does not bring Nibbana. Nibbana is found by ending craving.


  they must be highly motivated and diligent in their efforts, perhaps spanning many lifetimes.


There is no evidence for many lifetimes. Such ideas are only found in a certain genre of texts and also later texts. 


  Thus, it seems that to remain in Samsara requires much less desire and effort than to seek one's own annihilation via the Eightfold Path.


Eightfold Path does not lead to annihilation of life. Only the annihilation of suffering.


  existence 


Existence (bhava) is an idea; the idea or thought "I exist". It does not mean the existence of the mind &amp; body. 


  which all sentient beings


The Buddha never used the term "sentient beings". The Buddha taught "beings" are views or ideas born from strong attachment (refer to SN 23.2; SN 5.10).


  experience as subjective reality is all a deluded mind can ever know, so seeking to extinguish that reality seems like a desire for non-existence which is supposed to create more bad karma and rebirth.


Suicide is an action born from pain &amp; confusion. Suicide means the mind has not found peace from practising the Noble Eightfold Path. This is why suicide is regarded as bad karma because, instead of performing suicide, a person can practise the Path.


  I honestly struggle to follow the logic of this.


This struggle exists because Buddhism has not been studied &amp; learned accurately. Instead, your views about Buddhism, while very common, are the superstitions taught to children &amp; village peasants. Since a Buddha is fully enlightened, obviously what a Buddha teaches cannot be illogical.