Did you ever... get the feeling, that... you know, people... who are out to get you... might be right behind you. Right now. Right. Behind. You. Now. Don't look! Don't look! They'll just disappear.... And then come back again.... Watching you... from back there..... Watching...
They're probably all doing their own thing, not watching out for you. If your boss said that they're not that interested in helping you grow and develop skills. It's a part-time job too. They're probably trying to save money.
You could find ways to do new things that help you and help them at the same time. And make it obvious that you're looking for something new to do. Of course it's going to get old doing the same thing the same way over and over. Excel things can be automated, if you're not already doing that. Or cross-train with someone else. Interesting for you, good for the company if two people can do the same job.
If you're letting people walk over you, stop. If your landlord breaks terms on the lease, call them on it and continue to follow what you originally agreed to. If they raise the rent, you can always move -- But you can let them know ahead of time. It's their choice if they want to raise the rent, but if they do, you'll probably have to leave, and you'd like to stay, but... Be assertive without being a jerk. Toss the bs back in their court and them deal with it.
Landlord, boss, colleagues... even the Uni... It all sounds like it's money and work related. The university is trying to make money off you too. You can get screwed even if you do everything they say and you do well at it.
Maybe clarify expectations. Have a plan. Know where you want to go and what's acceptable or not. Bargain a little, like rent thing. Learn to say no without insulting someone. That type of thing. There are ways to spin things that will not insult or will put the emphasis on the other person so they're the bad guy if they make the wrong decision. "I'd like to help, but I'm really busy and want to do a good job. You don't still want me to work on that do you?" I wouldn't say that to a boss, but maybe to a colleague. To a boss, I'd say, "That's probably going to take x amount of time. I can either do x and focus on doing a good job on that, or I continue doing y which we've already agreed I should work on, but I won't be able to do x then. Let me know which way you want me to go on this." You don't exactly say no and you put the decision back on the other person.
For your current job, if you're bored with it, start asking for other stuff to work on. Other areas, anything. You could even (tactfully) tell your boss you need something new to keep you fresh, that you're starting to feel stale on what you're working on. If your boss is smart, they'll keep your work interesting. Because if they don't... What happens? You get bored and leave. You take a job that is more interesting. The boss has to hire and retrain someone. (So why not just train you to do more stuff anyway?) Then again, you're part-time. They may have created an extremely easy job where people are easily trained and replaced. If it's a brainless job, try to bring in something else you can work -- ie Try to practice while you work. Listen to music. Study something. Get your mind active on things that benefit you instead of devoting yourself solely to the work. Or don't work as hard. Most people can't tell the difference if you're working hard or hardly working.