Okay, so I'm going to be straight with you.
I personally wouldn't advise staying in a sexual relationship with someone like that. I'd suggest you lose this guy. Fast.
He refused to do what you needed for super-basic sexual safety -- a thing a majority of people need, for the record, to just do the most basic things they can to help prevent infections and pregnancy -- because his pleasure is more important to him than your health and safety. That is BAD NEWS, and I'm sure it's clear why. To boot, there are nonlatex condoms, and learning how to use them so they feel good is really easy. Millions of people have figured it out just fine. Usually, when guys say they don't like condoms, it's just a b.s. line, a way to see what someone will let them get away with/a way to exert control, or about a guy who can't be bothered to just learn how to use condoms, much in the same way that say, so many women learn to do basic things for their own health management like using pads or tampons, or using various kinds of birth control.
His "knowing what he's doing" (which it sounds like he doesn't, for the record -- he didn't even know to use lube, FFS, or how to stop when a partner is in pain -- unless he means he knows how to coerce someone) doesn't keep you safe. His talking you out of what you need for your own safety makes it clear just how *unsafe* he is.
You felt intimidated because this guy shut you down and coerced you -- which is a form of sexual abuse -- into doing something you didn't want to do. It also sounds like, for whatever reason, if he was just saying he wouldn't have sex if there was a condom involved, you didn't feel able to say, "Well, I won't if there isn't one, so obviously we're just not going to have sex together." I suspect a lot of why is because this is a controlling guy, and his control is working.
Someone like this isn't likely to be someone who is going to respect your limits and boundaries period. he may even be someone who feels powerful by being able to ignore them. You're not going to be able to convince a guy like this to use condoms because he obviously just doesn't give af about anything but getting his own rocks off. And someone like that not only isn't safe, you also probably are unlikely to ever have great sex with them because someone like that isn't likely to care enough about what you want and need for sex to be pleasurable for anyone but them.
I know that's a lot to toss at you: how do you feel about that? And how do you feel about only picking sexual partners who treat you with the kinds of basic respect and consideration this guy isn't (and likely won't)?
In terms of getting tested without involving your Mom, it just mostly comes down to being able to get yourself to a clinic where you can get tested. Are you able to get yourself places by foot, bike, the bus or some other way?