Getting him to wear a condom

This could be a really long story, but I'm going to make it as short as I can.
I recently had unprotected sex with an older guy that I don't really know super well (we have had friendly conversation for about a month). I never thought that I'd have unprotected sex - but the sex started so quickly I hardly had time to say anything. I know I could've and should've, but I didn't. And I enjoyed it, and in the heat of the moment, I just went with it. I didn't really start worrying about STDs until later. Even with most STDs, I know they're treatable so I don't REALLY get the big deal, unless I get herpes or HIV, both of which, I know could be possible (Actually the most worried about HIV).

This guy really enjoyed our time together and wants to see me again. I agreed to meeting with him, and I did forget my really expensive sunglasses at his house, and I'd really like them back. Of course, this means seeing him again, and I feel obligated to have sex with him again, although I know that I shouldn't. I enjoyed the sex, I just don't want to have unprotected sex again. How do I bring up using protection to him? I feel like because I had unprotected sex with him once, he'll expect me to do it again. I thought of buying condoms, but I'm not sure if I'd buy the right thing for him. I almost feel like I shouldn't have sex with him again at all, but I kind of want to. We mostly communicate by text. Should I just tell him to get what he wants? Or what. I already feel so bad and I'm so paranoid that I have STDs now.