The unfortunate case of a paper with extremely slow review process
I suggest just sending another email to the editor, and also send an email to a different editor just in case the first editor is on some kind of weird long sabbatical (it happens). With regard to the paper, your revisions didn't take that much time. After all, it took even longer for them to review it. If you still don't get a response in a month, I'd consider sending an email to this journal to cancel the submission process and then just submit it elsewhere.