Having to work while being in school is not ideal, but also not uncommon. Lots of people (me included) have done it successfully, so it’s absolutely possible with the right strategy.
If you already have problems with your mental health, this should be a priority. Make absolutely sure you are fit for uni, before starting! Otherwise the additional stress of the course load can have a big toll on your overall health and make you drop out. Seek counseling before attending.
The problem with multitasking (for a computer as well as for a human) is context switching. Constantly having to change between tasks (e.g. studying/work) costs a lot of mental resources, because you basically always have to focus anew on the current situation. So try to work and save the money during the lecture breaks and vacations, to focus solely on studying during the semesters.
Depending on your program, you might choose which classes to take for your degree. Find out exactly what classes are available and how they will be graded. In my experience classes that have final exams in the end of the semester are harder compared to those requiring the submission of a paper/essay or (group) projects. Exams always stressed the hell out of me, because no matter how good you were during the semester, the last few weeks always boil down to cramming books for different courses while the task of writing papers or doing projects can be distributed over a longer timespan. Choose the classes by the easiest grading methods, not so much by their topics.
Slightly off topic, but I would welcome an .onion of .i2p link as an alternative mirror for lemmy.ml.
If the configuration isn’t too difficult, it would allow users of tor or i2p to browse with more anonymity.