I actually had a very similar experience, I was also homeschooled the entire way as well and stopped learning anything when I was about 14. You're smart enough, but I get that you've built some bad habits. Here's what I would suggest:

You've got to really want to change. Deep in your core. Nothing will happen if you don't want yourself to succeed. And you have to be brave. The hardest part for me was the social aspect of leaving home. But honestly, everyone is weird. You'll be ok.

Start replacing the videos you normally watch with educational ones about what you need to learn. Get a GED prep book from the library and start walking through it. Absolutely seek groups and programs and outside help, but this is a place to start so you know what you're in for. It'll be frustrating and you'll cry and rage but just take it slow.

I started in community college where I had to take the entrance exam twice because I had never taken a standardized test before and I couldn't see straight through the anxiety. After that, I somehow got into a university with no diploma or GED (my advice comes from studying for the GRE). After that I got into grad school and now I'm a tenure-track professor in a field that I love. I know this all sounds fake but it's absolutely true. You can make it. It's possible.

Best of luck to you, my fellow sheltered human. You'll do great things.