Also, the argument of an evil demon denying you the proof of your existence by deceiving you with thoughts that are not yours is addressed in Meditations on First Philosophy, one can't be deceived unless one existed in order to be deceived:
But I have convinced myself that there is absolutely nothing in the world, no sky, no earth, no minds, no bodies. Does it now follow that I, too, do not exist? No. If I convinced myself of something [or thought anything at all], then I certainly existed. But there is a deceiver of supreme power and cunning who deliberately and constantly deceives me. In that case, I, too, undoubtedly exist, if he deceives me; and let him deceive me as much as he can, he will never bring it about that I am nothing, so long as I think that I am something. So, after considering everything very thoroughly, I must finally conclude that the proposition, I am, I exist, is necessarily true whenever it is put forward by me or conceived in my mind.
Solving the solipsism problem is left as an exercise to the reader. Recommended reading: https://www.iep.utm.edu/solipsis/