Is it normal to cry for no reason whatsoever?

For a few years now, I've developed weird and abnormal habits. For example, when I play combat games, my hands start to shake madly. I've always assumed it's because of my fear of failure. I have this fear all the time. When I take quizzes, I always have a strong urge to cheat to avoid failing even when I've studied. I also have intense breakdowns when I do fail or I feel "stuck" in a situation I don't wanna be in. Kind of like a cat in a corner. I also have lots of weird episodes like my mind is attacking itself with my regrets and fears and it just won't leave me alone. The only way I'm able to ignore it is using self medication (gaming, art, watching tv, talking to my friends, etc.)
I remember when I lost a friend due to my insecurities. I had fallen hard for their personality and I couldn't help but feel the pain of them not even caring. I got so hopelessly attached. I begged and begged for them not to leave and that I was sorry. When they didn't respond, I knew it was over. I curled up in a ball and uncontrollably cried for at least 15 minutes, hardly able to breathe. I didn't even know what to do. I didn't want to kill myself because it would hurt the people around me in the end, but that was the only option running through my head. I've pushed so many people away with my feelings. I've always thought that maybe it was anxiety. I had a lot of the symptoms..or even depression. It would all sort of come in waves and I'd never know why. I tried to tell my dad that I might have an issue and he of course didn't believe me.
I remember the other day when he tried to mock me by saying "oh so what did you do? Have a panic attack and cry on the floor?" and I responded with "well maybe that's where I was". He just sat there in total disbelief and continued to deny me. I guess he'll know something's wrong with me when I drive my car off the road from insanity or scratch up my entire face...again. Smh he never listens to my cries.