I'm glad your BF is now receptive of your fantasies but you should consult relationship advice regardless. The Relationship Geeks Signal group invite link I sent you is a good starting point but you (both, ideally) should go to a local counselling place for professional, Czechia-specific advice, especially considering the near-breakups.

As for finding dick... It won't be hard to find men attracted to you but don't forget bigots and creeps don't deserve your body! Don't let them think they can take it, it will just give them courage to unconsensually attack other vulnerable people, and please don't make it worse for women and trans folk! Sex with a person who actually deeply hates your identity will hurt you, and not in a sexy way.

There are safe spaces for you to look for a relationship that involves sex, though, like around universities. Czech students are overwhelmingly allies and just as horny as other people in their early 20s. Bring condoms, wear them on a necklace if you want to be really explicit 😅 Lessons start next week, and in common areas like the library, canteen or bar, you'll see people your age looking for friendships even outside their faculty. If other allies are anything like me, they will approach you just for having a Blåhaj or another more or less overt trans symbol. Your BF can come too, it's common to bring one's SO to student socialization.