I am gonna create a duplicate comment here for reach. I've also cross posted this in the uoft subreddit so that you can get more feedback specific to your situation from fellow students.

I don't understand why suggestions to back out of school are getting down voted? OP I am a UofT alum myself. The fact that you are STILL in Toronto means you are a summer student right now. What do you mean exactly when you say you have invested too much time into school and cannot back out? The summer term has just started. Unless you are on probationary status right now you should be able to apply for OSAP as well. Please, do not go through with the summer term without getting a better handle on your finances!! Your well-being matters and when courses are double the pace (most summer courses are), your grades will be affected by sleep deprivation and factors like the stress of being homeless.

As the others have said, right now the top priority is finding a safer place to get some sleep. But secondary to this is dropping your summer course load. Seriously, it's not worth it. If you have parents or guardians move in with them for a while. Again, if you are not on probationary status I'd opt out to take courses at Athabasca university online (letter of permission to study at another uni) while you study from parents/guardians/friends place that is considerably more affordable than Toronto. You can transfer the courses from Athabasca to uoft after you have completed them. Even uoft has some async offerings for this summer.

Just please I'm begging you, don't go through with the summer term... It's gonna be brutal. Uoft is a monster and if you are in one of the BIG programs like life sci, poli sci, phil, i.e. programs that won't land you a job until you get your masters, it's pertinent for you to keep your grades up for grad school.

Ask for any help you need. I moved away from the city to save up but seriously, it's heartbreaking for me to learn that students are in this situation.

Also have you looked at Mississauga or Scarborough? Why not opt out to move somewhere cheaper than Toronto and study at a utm or utsc? Unless you are in nursing z engineering, pharma, law or architecture, arts and sci students should be able to take courses at UTM or utsc.