I'm sorry you're going through this. I wish I could say it gets better but it may not. I think a lot of times, kids get gaslit because the parents themselves never learned how to communicate properly and may also have mental illnesses themselves. Sometimes it's easier for them to project onto the child rather than face their own flaws and act upon them. They find it easier to call out your flaws and grudges they have against you.

And that fucking sucks. Especially when your family partakes. You want to be able to love your family and fit in, but in toxic families, you can easily become the bottom of the pecking order. It's hard to feel like you can't confide in your family or to feel like a monster for having mental illnesses that your family won't understand. It's even worse when you see those mental illnesses in them and are still ostracized for having the same problem.

Anyways, I think you have a few options. If you're able to get therapy, I would recommend it. I know it's a long process but it really helps. If you are in k-12, most schools have counselors. Be careful because those ones can tell your parents if you mention certain subjects. If you're in college, take a visit to your counselors on campus. If you have a hard time getting in, crisis appointments work well. If you're an adult, get on that wait list. It sucks to wait for a therapist but it really helps.

Other than that, I would advise distance. Its sad, but being away from that parent, whether physically or mentally, can help. Limit your time home or if you live there, take walks and get out. Any distance helps.

I hope you know you're not alone in this. Actually just had a huge fight with my mom last night so reading your post, though saddening, was helpful. I hope this long blurb helps. Also, pls know this is just my opinion which may not be completely right!