I'm going to stop talking to a guy I've been seeing because he's struggling so much
Why would you stop talking to someone who is struggling?
It is just tough to see him struggle. I want him to get his act together.
You are being selfish and unavailable by not talking to your friend because he is struggling. You should be available for your friends when they need you to be. If you are not, your friend will not be available for you when you need him.
I don't want him to feel like I'm using him. I'm broke and I need someone to spend money on me.
If you do not want him to feel like this then you should probably just tell him. Leaving him during his struggle is only going to make the struggle worse. You may be able to really help him feel more positive despite of whatever situation he may be in.