First time posting here and I wanted to know if my situation needs professional help or maybe I can remedy my way out of this

I've started feeling like this ever since I was small, like in kindergarten. Places with many people overwhelm me so I try to walk in corners because it makes me feel safe. Everytime I go outside alone I always feel stiff and I get intrusive thoughts that keeps saying the same things over and over like "I definitely look stupid walking" or "I must look really embarassing right now" but I can somehow manage when someone is with me or when I'm wearing a face mask. When in a social setting or public place, I need to constantly distract myself with something otherwise I get nervous (constantly checking my phone, fiddling with my fingers, etc) . Deadlines make me nervous so much that I procrastinate a lot and barely get anything done. I'm always late for university classes because I suddenly get scared when I have to go to school. Like, I'm all dressed and still have 15 mins left but I idle myself around our (my brother and I share the same apartment) apartment by walking around, looking at the time pass by and would only leave when I realize I'm late for first period. At night, when I'm alone I get needlessly get nervous about monsters intruding and attacking me that I get palpitations and sweat really hard. It also doesn't help that I cry at night most days of the week for reasons I don't know why. Although there was a time when I actually felt better. I didn't feel as nervous when I went shopping on my own. I think it was when I had routinely home workouts back in summer, but because of university I barely have the time to move my body so I started reverting back to my old habits. 
So what do you guys think? I'm thinking this might be a problem but I've been living like this my whole life that I can't tell if I'm suffering from mental illness or not. I don't know how severe this is, or if it needs medical attention, but recently I started thinking to myself that I don't wanna cry so much and be overly sensitive anymore, I want to walk with confidence and interact normally with my classmates. But it's proving to be very difficult because I'm nervous I might mess up or say something weird or look funny to them.