i’m writing my thesis at the moment and struggling with the same problem though my university is still open i still have to write my thesis on my own and do my own planning  it’s a literal nightmare even though the topic of the thesis is very interesting to me   for me it worked to meet with my sister a couple times a week and sit in the library together she is writing her thesis too but doesn’t have adhd she has really good organisation skills it really helps to have a buddy that is holding me accountable so my advise would be to have a buddy or ask someone to help you with this inform professors about your problem so they know you struggle with it and maybe they have a solution as well