Thank you so much Guilloche! Yes, I'm a typical introvert. I find talking exhausting. But what's interesting is that I can be funny with kids when it's a part of lesson plan. Such as role plays, songs and dancing or making crafts. My mum was in the next room recently and she commented about how I made that child laugh and she heard her giggling whole lesson. But the thing is I can only do that when it's planned or an instruction that I read in the teaching manual. I can't do this sort of things when I don't have a clear how to guide. Which I don't have in 99% of situations. And it's not a good idea to talk to adults making funny voices, right?
I think this goes deeper, to the core of my mental issues because I find it very difficult to do anything unless I get Instructions and know exactly what is expected of me. I also learned that mostly when I spoke about my interests I was called boring or weird (in childhood) so nowadays as an adult I miss instruction about what I have to do and I find it difficult to play my expected role in conversation. However it's not that I know what would I say if I could! The problem is I don't know what I want to say.
It's absolutely the worst when people ask me how I am. In my culture, it is expected to actually answer the question. You should say what you're doing that day or complain about something or talk about your medical issues (e.g.back pain). If you only say "fine thanks" it's a polite way of suggesting you're not interested in the conversation.
It's worst when my former colleague from work who's trying to be polite and talk to me but I always answer "I'm fine thanks" as if I didn't want to talk to her... I'll have to prepare the answer for this but nothing comes to my mind...
I'm just terrible. Sometimes I feel like a person with mild aspergers. Or maybe it's a result of life long situation where I was expected to say and do the right thing, both at home and with my "friends". And now suddenly when I'd like to be natural and relaxed I have no idea how to do it. I'll need to discuss this with my T.
Also sometimes when I talk and the other person seems to be listening I panic because I get anxious "they are paying attention to me, I can't embarrass myself now". Then I sometimes stutter or something like that. It's different when I'm explaining stuff to my students. I have my instructions and know exactly what to say and do because I prepare in advance. However as soon as the lesson ends I'm lost again.
I'll check out the series you mention, thanks.

Nouaeforaname thank you for your reply, I think you're a cool person :-)