Question: I will preface my question by stating I am very new to writing and new to this website. I am here for help.

I'm writing a collection of inspirational short stories, as though I was sitting across from someone over coffee sharing my experiences. Because my normal manner of speaking is in passive voice, I am struggling desperately to convert over to active voice, which is basically stifling the flow of my thoughts and words, making them almost stiff and impersonal. 

I have been studying the grammar rules and know exactly what needs to be done, but I am stuck - what is the best advice you can offer for someone in my situation? I am not ashamed or embarrassed to ask this but would appreciate your input. Thank you.

Answer: 
Consider finishing your draft before trying to do active voice and instead changing things to active prose in your revisions. 

Active vs passive voice usually reads better, but it does not change the meaning of the text it just makes it seem more energetic and immediate. Therefore it is not like you will have to restructure huge pieces of plots or similar if you want to change it later. So it is good to do it in late revisions. 

Improving prose is something that is usally good to save until late revisions. (If you do it in early revisions or in your initial draft there might be large parts you end up not using or you have to rewrite a chapter because the plot doesnt work or you want to change a character and suddenly you have wasted a lot of effort improving prose you are scrapping and rewriting anyway)

And obviously if you just write great from the start you'll have less revising to do in the future, but if trying to write great stops your drafting process there is nothing unusual with saving it for later and just producing the words.
Do you know someone who speaks in an active voice?

If so then a simple method is to have that person (In your minds eye) speak your dialogue to you.

Alternatively, if you have a favourite character who uses active voice, then that is another possible person you have speak this dialogue to you.

With this kind of visualisation I find it helpful to be in a quiet room - or have my headphones on - to completely isolate myself from outside stimulus. I will also have my eyes closed. Then I spend some time first getting into the head of the person or character I want to "speak" the dialogue.

Then I will have them do so in my head. For me personally I also find that if I try to do any of this out load it doesn't work very well - the sound of my own voice gets in the way.

Let things slow down - try to frame things a small concept at a time. Once it begins, it will flow naturally. Keep rolling with it and after a while you should be able to begin recording what your character is saying.