How do I stop sabotaging myself?

The easiest way would be to join a club. Or start an easy conversation. For girls, my sisters thinks the easiest way is to start off with a compliment lol. I was with her once and she started a conversation about how much she liked someone's dress, asked where they had gotten it, somehow got the topic into dresses having pockets (which is a big deal I guess?), and it just turned into a normal conversation.
After we walked away, she had been invited to join a club the girl was in and was kind-of already friends with her. I asked her if she was going to go to the store that the girl had said to look for the dress she had asked about, but apparently that was just a lead-in to get into a conversation, because my sister had seen the girl around and wanted to be friends.
Boys have it way easier. They can just invite each other to play video games or watch a game lol. But even then, most of my friends I met through sports, school, or clubs.

Feel for you, introverts unite 😃
Someone said it earlier, clubs are perfect, they usually have a structure and a purpose so the small-talk is minimal and often focussed on the subject.

Book clubs
D&D groups (often full of fellow introverts)
Sports
There's usually a load to choose from. Look at meetup.com for ideas or local activities

Join an organization or something that is of service to others. I was a hopelessly shy geek at your age and helping others made it easier to converse. I think your issue might be low self esteem and worth. Learn to love the young woman in the mirror. God makes no junk. 😀

Silly. Go to the dang library and sit on the aisle seat. You can pretend to read, yet also look up if by distraction. Eye contact follows. Smile....project warmth....
Stay away from phreaks and pervs. I suspect they like libraries....🙄

DRINK ALCOHOL

When I was in undergrad I was the same way. I discovered alcohol in my junior year and it changed everything. I could talk to random strangers for hours.

I’m kinda of an introvert too. I know it’s hard to do but see if you can find people with the same interests as you have and there’s nothing wrong with small talk

Pretend u’re sociable and respond when spoken to. When u mastered that, initiate a conversation.

Maybe join a club of a sort if there are any at your college

Push past your feelings. Accept that this will cause some anxious or stressful days and you might feel or look dumb a few times. Don't be fake to be social. Find other introverts. They exist but it can be hard to get to know them. Join a club, group or whatever if you are truly interested in that topic.

Hold your head up, Make eye contact. Smile occasionally. Ask people questions and just listen.
People love to talk about themselves actually so you can make friends just by listening and the occasional insert, "oh really, but why, and then what happened". Most hardly notice that you aren't really saying anything but once this gets you in the door don't let your friendship stay that way.

It's too one sided and not respectful if they never ask you anything. But even if you aren't super invested in your new acquaintance, you can use them to meet other people and the more people that you meet the more odds are in your favor of finding a real friend.
Cut off toxic or disrespectful people quickly. They suck the joy from your life and can really set you back in various ways.

Have a drink. Not too many, just a little.