He may be trying to get more attention even though it's now by being bad. Since you had been home for so long and giving him so much attention he became used to that and maybe this is why he's started peeing on your bed.

The other thing I'd advise is to make sure that he doesn't have any health problems. You should probably have him checked out by a vet to make sure it's just a behavioral problem and not a physical one. Good luck and please continue to keep us updated.