It’s all hypothetical right now, because that place could be perfectly fine. But no, you can’t fix something like that from the inside. Trying to do so would not address the main issues and could even lead to trapping water in the wall which would be bad. The foundation would need to be excavated. The damaged walls rebuilt or repaired. House may need to be lifted off the foundation. Horror show. I don’t think any of that is the case with this place though. But I’m not there, and also just a random on the internet. This is an enormous decision for you. If something in your gut is telling you to run, then run.