Howto start talking w people again after years of isolation?

While kindergarten and grade school days are often spent building friendships for other children,I often found these times rather challenging socially. I wanted so bad to fit in and to not let my parents down but whenever I tried to make friends I kept failing, because of my naiveness and my lack of understanding how to start a conversation and how to keep it going.
Even just playing with other children was hard, first of all because i thought that playing was stupid (I didn't see the point of it), and second of all because playing required talking and I was bad at that.

Nothing smart came out of mouth apparently, because when I was 7 the only friend I had, thought i wasn't good enough and started making fun of me. The thing is that ever since I was in kindergarten the talking-mode wasn't my automatic mode: I was a quiet person who enjoed talking to others only when there was a very compelling reason to do so. Why waste my energy for nothing, I thought? In grade school I learned that it wasn't for nothing, that other people had feelings too and that by talking I could make them feel something and I could feel something too.

After I realized that, I tried to be friends with the boy sitting next to me at school, but he seemed to dislike me for some reason so I stopped trying. My self-esteem was very low at that point. Everybody disliked me because they thought i was too stupid. So I just kept observing them, as if they were animals at the zoo, in order to understand how they functioned.

Then in 7th grade I started making friends again, after a classmate invited me to sit next to her on the first day of school. I was surprised, because the year before she ignored me. She was my first friend after a long time, and then my social circle expanded, and I was able to talk to all my classmates, and be funny and smart (because I learned how to copy the way people my age communicate).

But I was fighting a battle inside. I didn't know why by I started feeling really sad. So i asked myself why. I think it was because even if I was talking, my communication seemed like a performance. All the gestures that I had to make, all the voice intonations that I had to make seemed forced, as if I was trying too hard to enteirtain my friends, because indeed I'm not really a social person.
When I was social, I had to fake it so that I can appear more "normal". I felt different and like I was lonely in a crowd.

In 8th I started to feel too overwelmed with being social, so i started to isolate myself again. I've been isolated for 90% of my life. I spent my high school years alone and depressed. I even started to believe in god because I didn't want to be alone anymore, and communicating with other people was too hard because of my depression (I didn't have the energy to do anything). But my religious phase was just that, a phase. My depression was so overwhelming that I stopped having hope and faith in a higher power. I was on the brink of killing myself.

Then my teacher noticed that my grades where dropping and that I was having emotional problems (I cried in school many times) and she called my mom, and they thought I should see a therapist. Therapy didn't help so my T sent to to a psychiatrist who diagnosed me with major depression. It's been 5 years since I've taken my first mental health drug.

The medication benefited my mood a lot, but I still feel that the cause of my depression is that I can't communicate with others (I haven't talked to anyone since I was 13 so I lost practice). So I still feel a little bit depressed. And this, I think, can't be cured with medicine, but by going out and meeting people. The only problem is that I don't know how to start. I even feel that people in this topic are going to make fun of me. Do you have any advice for someone with poor social skills and with a ridiculously low level of self-esteem?

Thats a very interesting post! Your skills in communication can not be that bad if you are able to write something like that. Maybe you could pick a hobby that includes a bit of socializing. It is not really important what it is, chess or theatre or growing pidgeons... this way you would meet people who „share the same interest“, so there would always be a topic to fall back to.
During my rehab I had some „social skill“ workshops, maybe this is another option for you to make some progress.
And do not let one single bad experience with therapy keep you from trying to find a supportive and understanding therapist... you seem to be well structured, I doubt there is no way to work on your issue this way. I would be happy to get a prompt from you, sorry, did not see your post earlier.