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: 
Don't worry about it in your first draft. It's hard enough to finish a first draft, don't make it harder by trying to write perfectly. Just get your story out and fix it later.

Especially since you're working on short pieces, you can devote your revisions to individual issues. Read through once just to look for passive voice. Read through again just to look for weak verbs. Read through again, listening to awkward phrasing. Rinse and repeat.
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.