TL;DR: I ghosted (i.e. suddenly ceased communication with no explanation) my previous supervisor for 2 weeks when I had to do some minor final job regarding to my already finished thesis work due to my stress level. He now probably thinks I am unreliable and ghosted him forever. I actually want to finish the work and fulfil my promises, but have no access to the computer I worked on anymore. How could I improve my situation and reply to my professor to save what remains of the seemingly burning bridge?
I did my Master's thesis as an Erasmus student, started during my exchange term, and finished it the next term when I was at home. My fields is physics, and the thesis work involved the development of a complex experiment setup automation software in LabView. During the second term I was developing this remotely over Team Viewer. Most of the work was done during my exchange and the work later only involved smaller bug fixes/improvements.
My supervisor was happy with my work. In fact, he offered me a PhD position, which I was considering until a better opportunity, shared work and fast-track PhD in a science facility, came along.
Due to the COVID events in the 2nd term (first half of 2020), and because my new full-time work already started in the middle of May, I had some serious deadline problems with my Erasmus paperwork and the thesis itself. I have to admit that these were on my responsibility, due to bad time management and mental health. This ended up by submitting my thesis with a few modifications left to do (only improvements, not changes of result). We made a discussion with this professor that I would still make these changes, and also do a last bunch of small modifications (doable in 1-2h) on the program to make it a final version. He was positive, and he actually still offered me a possible collaboration including experimental work at that university, should my current boss/supervisor (he is both) also approve. (My ex-supervisor and current supervisor work on the same field, and they know each other personally.)
The problem is a serious mistake on my part. Just after this discussion and the successful defense of my thesis, I had to start working in office instead of home office as before. This greatly increased my workload and - as a first-time worker - stress. I had my personal issues also, but at the end, I just made a serious mistake.
I effectively ghosted my previous supervisor for the past 15 days.
We communicated over Skype, and he asked me about a week ago if I finished the modifications. The first time I read it I actually got myself to it and finished 80% of them, but there is still one left (doable in 20 min), and I also didn't make the changes on my thesis work. I ended up with the stupid decision of not answering. Then about 3 days later a follow up message came, asking the same thing. I didn't reply.
I have no good reasons, even for myself, why I did so. Basically I believe I was in almost constant fight-or-flight mode during the past two weeks due to my stress levels, and I have a very bad and hard to fight psychological trait of completely hiding (ignoring, denying it's existence) from problems causing high stress. (I know this is horrible, and I do work on it, but that doesn't matter regarding the result.) The point is, I messed up and would like to save my relationship as much as possible.
This weekend I finally got my butt together and made me face the problem. I wanted to fix the remaining problem and my thesis work, so I can write a positive, albeit very apologetic answer.
Only to find out I can't access to the computer via TeamViewer anymore. We discussed in the past that when I finish, TV will be removed to reduce risk factors, but I was not notified of this. My guess is my professor (rightfully) thought I ghosted him forever and will not fulfill my promises, I would guess from the circumstances and the lack of notification that he is not the happiest with it. I would like to address this and save my relationship with him as much as possible, but I'm not sure how to proceed. I have to face that I did make serious mistakes and came down as lazy and unreliable, even though I had my reasons/problems. And I'm at a loss on what to do as the next step.
How could I respond to the professor to achieve the best possible outcome, and save my situation as much as possible?