Fellow lonely person here. No, it's definitely just loneliness.

I hate the mantra I've often heard spewed that "if you stop looking for friends/a significant other/whatever", they will naturally come to you. No, just no. For a small portion of people, they are lucky enough that this happens to them. But for the majority of people, finding relationships takes work.

As a kid, it was easy. Adult life is different and relationships no longer just fall into your lap like they did when you were in school. Ever hear people lament that making friends is harder as an adult? It legitimately is. We get caught up in work and home life and don't necessarily have all these extracurriculars to meet people that we may have had as kids or young adults.

I don't have the answers to OP's specific scenario, as I've always struggled with this too. But telling someone "no, you're not lonely" when they've expressed their loneliness...and telling someone "don't bother seeking people out, they will come to you" is incredibly counterproductive "advice."

Edit: I did some reading and it appears that OP is intending to transition. It's incredibly unfortunate that unsupportive people exist nowadays and it must be hard to suddenly lose your friends and family like that. But the solution isn't to stay there. It's to leave and find a community of people that accept you. People won't just magically come to you unless you stumble on a stroke of luck. You have to seek them out yourself.