Be more open about my feelings

I’m just sitting here crying because I’m very confused. I’m in school and I feel unmotivated to do anything. The only person I really talk to about my feelings is my sister but I know she has her only life and problems and I hate making her upset with mine. I just dont feel that close to any one else that i feel like its ok to tell them things that are personal. Sometimes I think I’m quite depressed. I just feel like there are so many reasons I dont want to say what’s on my mind mostly because I’m nervous that I’m gonna be criticized. I never feel that it is normal plus I dont want people to just pity me. I sometimes write things but that doesnt help as much. I want to have good friends but I feel like this may keep me from having friends at all in the end. I’m always surrounded by people and lonely & wanting to do new things but feeling trapped by my shy awkwardness. I’m tired of trying to act perfect and like I know it all. I act like I’m confident but it gets really hard to pretend. I wasn’t always like this, it’s sorta stressing me out. Sorry this is so long but this is the most open I’ve been and I just want to get some other person’s take on it. Is it a good idea to tell this to strangers rather than people I know? What’s wrong with me and what should i do?

Can anyone give me some advice on how you did this because im trying to put myself out there but it’s hard to get in that frame of mind. any tricks??