I did have some symptoms of high testosterone, but I also had PCOS. AFAIK, even with a condition like this where my T levels were elevated, it wasn't enough to do things like lower my voice, give me any downstairs growth, or redistribute my fat. All I got was some random facial hair, thicker body hair, and skin issues from puberty onward. And there was still a noticeable difference in all of those things when I started T at 25.
I don't think it is possible to have a puberty that is delayed until mid-twenties. But if it helps you to believe that's what it is, then go for it. How positive are you that you don't have PCOS? It could definitely be related to your thyroid issues, and I would encourage you to see a doctor to get your levels looked at. And even if they pressured you to take E to balance things out, you don't have to. That's your choice. You'd just be living with higher T levels.
If T feels out of reach at the moment, you could look into natural transitioning. Some guys have luck with it, some don't. You basically have to eat and exercise like a bodybuilder to see any significant difference, but it may help you feel like you're making progress.