I get not being able to throw parties at your own home and having money issues, but I think you still need to make the first move. Like, asking people to go to the movies together (not super cheap, but once in a while maybe?), or to just grab a coffee somewhere (not free, but if you eat before and really just have a coffee?). Or look up things that are free & going on in your city, and ask people to accompany you? Even/especially if it's a bit out of your comfort zone?
Or if you like running, maybe ask people if they want to join you?

Even if they say no, you might eventually be on their radar for social things again.