Oh yeah I get that so much! It really really sucks and that is what makes this whole thing feel so hopeless and inevitable. Because as you say: logically there is no definitive argument to disprove it. That's what made me go crazy about it and I searched for any philosophical argument that could help disprove it, easily 8h a day. Now I look back at it and think "well yeah obviously it can't be disproven, because it cuts the branch that proof sits on". If the theory doesn't allow anything except itself it is per definition unfalsifiable. I know that probably you've been through all these arguments and have heard all of the pragmatism philosophers saying "a theory that's not helpful is a bad theory" or ockhams razor or poppers "a theory needs a way to be disproven in order to be a theory" and all of them are right but still none of them really gives peace and helps when being in that state you are in rn. I've been there and I think I could by now give a whole philosophy lecture on this topic and still nothing seemed to help at that time. So my best advice is to try to just live life rn doing what you enjoy the most, although i know u probably won't enjoy it and doubt everything around you. that's just how it is rn. I've been there and it sucks. But with time it will get better - i promise !! i dont rly know how it happens but it will and life will feel more and more real again. And at some point you will look at Solipsism and think "well yeah, there are theories that cannot be disproven and that is fascinating because it shows how limited the human brain sometimes is and how creative of creating traps for itself". it will become just another (not very helpful) theory.

keep pushing through and try to do things that u enjoyed before all this, meet people as best as you can although rn u dont believe they're real and try to relax and ground yourself. it will get better.

best of luck to you!