At this juncture, the advice below is not likely to help (if I'm in a boot loop that isn't resolving, repair install or reinstall are the options I go for). Might work if you use a live environment though!
Possibly look through your package manager logs -
If you can get that dumped, you might be able to spot what's missing and try manually re-installing it, or at least get a list of all the things you need to reinstall.