Boyfriend and money

My boyfriend who is 27 (28 tomorrow is his birthday) and I 22 have been together for a little over two years. Over the years my boyfriend has had a couple different jobs. He’s very well paid in my opinion reaching 70k yearly. I work retail so not nearly as much as him and I’m going to be going back to school in a few months.

A little over a year ago he left the job he was at and had another lined up but had to move apartments. Once he found one he told me how much he liked it all the goodies and then asked if I could put the deposit down for it which was 1k I agreed because I had extra money at the time. then he was traveling for the job everything to him was inclusive they paid for everything. He was set. Once he got to the hotel where he was staying he said the ceo that he was traveling with was not at the hotel yet and they both had to put down 200 for one room he complained for awhile that it was hot outside and he can’t get into the room. So I ended up giving him the 200 to get in. He’s also a very big football fan and twice I had to spare him money 200+ per ticket to see the team. Recently I had to lend him 600$ because of traveling fees. I’ve had his back many more little times which add up. And by now my accounts are running low. He’s supposed to be moving out of that apartment and in with me and my dad to save money for a house together. He talked to my dad and said he was going to help him out with bills and anything else he needed since he is going to stay here I buy the groceries usually and he told me that he would buy them and that I wouldn’t have to worry about anything and that he was going to support me and my dad. Recently it’s been on my mind if he’s really going to pull through of if I’m going to have to support him in all on top of myself working only retail at the moment. This summer I’m working a side job so I will be working 7 days a week just to rebuild myself. I’m someone who can’t say “no” and I am really trying to get overcome it. I need advice. I feel like saying no is letting someone down. Or I feel like it’s not supporting.