Yep, I'm exactly the same way: I feel I'm too ugly to bother with makeup, I'm introverted, I'm not diagnosed but probably autistic.
Those are sorta mental hurdles to overcome, though - developing that skill so that the makeup you manage to put on is beautifying and feminizing is still worth it. It doesn't really matter how ugly you are, using makeup the right way will help. (If anything the logic flows the other way, the uglier you are, the more makeup is necessary and helpful; I certainly used makeup a lot more earlier in my transition, and less later in my transition.)
In early transition, makeup was an essential lifeline and a way to survive, and good makeup was a difference between passing or not. Now that I'm viewed as female whether I wear makeup or not, I just don't have to do as much.
To get out of your rut, if you feel motivated to, I would lean on your community more - go to trans support groups and LGBT+ events, go to pride parades, etc. and make friends. Find a femme and see if she will teach you how to do makeup. Let femmes put makeup on you. Then as you're learning from those experiences, start watching makeup tutorials and trying out the suggestions you find - particularly geared towards trans women and feminizing the face.
Once your skills are good enough, the makeup will be self-justifying, you won't have all these questions about why to bother - because you'll know why, because the makeup makes you look pretty, more like a woman, etc.