

Dont have sex with assholes. Because while you stood your ground regarding the use of barriers, afterwards you obviously still feel bad and unsure about yourself. Also if you meet him again, he most likely will keep pushing you to not use a condom.
Also the way the dude acted makes me assume he actually sucks at sex, because he seems selfish, inconsiderate and also uneductated regarding safer sex practices.

He treates you badly and now you feel bad. Thats totally normal and okay. Now my suggestion would be to put a stop to this bad treatment of you blocking his private contact and staying professional at your org. That sends a clear enough message