Then your problem is a corrupted blockchain (whether or not your wallet has anything to do with it) so unfortunately you are simply going to have to repair that before trying to use your original wallet again.

I would suggest you consider setting up a separate machine (or VM) for working on this and keep a copy of the blockchain (once you have the full uncorrupted version) somewhere handy.

The point being that if it was due to your wallet's size that somehow the blockchain got corrupted (unlikely but I guess possible) then you might find that as soon as you put back your big wallet and restart it might corrupt the blockchain again (putting you back to square one).

So once you have a clean blockchain (with an empty wallet) back that up (the whole thing) before trying to put back in you big wallet.