The unfortunate case of a paper with extremely slow review process One of the first papers I ever wrote has a rather unfortunate history. Mistakes were made, especially by me, and after around 3+ years the paper remains unpublished. Below is a rough timeline of how things progressed (or rather failed to progress). Any advice on how to proceed would be greatly appreciated.

04/2015: The paper is first sent to the journal. At the time, I'm in the second year of my PhD.

06/2015: The paper gets sent back to me because the bibliography is missing (basically: I accidentally run latex one too few times before sending). I promptly return the corrected version.

10/2016: I write to the Editor to ask about the status of the paper and receive no reply.

01/2017: I consult my Supervisor about the situation and he writes an email to the Editor.

02/2017: I receive an email from the Editor explaining that they had trouble finding reviewers and giving me suggestions about how to improve the paper. The gist was that the result is interesting but the exposition is inadequate, and I wholeheartedly agree with the second part (the 2015 version of me was a terrible writer). 

06/2017: I finally receive the review, which is mostly positive but also points to problems with exposition. The email also mentions that the paper is "tentatively accepted for publication (...) subject to revision". 

Now, what I should have done at this point is to correct the paper and send in the revised manuscript. Unfortunately, two issues came in the way. First, my thesis defence was approaching and I honestly could not find time nor energy for much else. The thesis ended up being rather unrelated to the unfortunate paper (the paper answers a question that somebody asked and I realised I could answer, it's in my field but not quite my subfield) so these two tasks were not related. Second, I came to realise that to make it a decent paper, the technical sections would need an almost complete overhaul, which made the task very unappealing (not only would it be very time consuming but also it would be a constant reminder of the poor quality of my previous writting). (The material was formally correct, but extremely inelegant.) In the end, weeks and then months went by, and there was always something that required more urgent attention (at least in my mind). Finally, I reworked the paper this summer and so:

08/2018: I send the revised manuscript to the Editor, with apologies for the highly inappropriate delay. I receive no answer.

09/2018: I send another email with apologies, politely asking if they could tell me what the status of the paper is (are they still willing to consider it for publication, etc.). Still no answer.

Now I'm at a loss of what to do, and unsure about what will happen. Should I keep badgering the Editor hoping for an answer? Should I take any other steps, or should I just wait for their reply? Is it likely that the paper eventually gets published?
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.