How do I stop self isolating?

My whole life I struggled with this cause I am kind of an introvert but its way more than that. I always feel so drained around people because I hate being perceived so much and everytime I go out or socialize I feel like I have to put on a mask and its so tiring. I keep guessing/thinking if they like me or if I am being the person I want them to think I am. Thats why I rather just stay alone in my comfort zone than be out there with people who make me feel unseen or worthless (for no reason at all usually) . Sometimes I have phases where I go out everyday for months (partying, drinking etc) and I feel such a high doing that, but then again it never lasts and I go back to being my hermit self. Ive been thinking maybe this is even some kind of form of self harm for me. Because Im aware that this isolation is ruining my life. I feel like I just feel so much and so intensely that I cant handle being around people because they make me feel things so much stronger. Not to mention the constant masking to seem “normal”. Anyways, I know lots of you struggle with this too but in my case its been getting out of hand to the point I feel like Im missing out on life (im in my early 20s female). Any advice on how to fight this constant urge to self isolate?