Good good good. There is a time in every thesis when it all looks hopelessly bleak and desperate and pointless; sometimes, the situation IS bleak and desperate and pointless, but more often than not it is just excessive perfectionism/paranoia/fear-of-failure/[insert issue here]. Obviously I can't say either way for you, and so my advice is pretty thin, but I'm glad you are exploring the issue rather than running for the hills.

You strike me as an incredibly intelligent, thorough person so honestly I will be shocked if your thesis project is as hopeless as you believe it to be.

Three months would be tight, but believe me, it HAS been done. And can be done again.

Good luck!