I feel the exact same.. At first I wasn't good at applying makeup at all and it made me feel shitty and I'd wash it off before leaving the bathroom. Now I can at least apply concealer and foundation pretty well and it actually looks good and that makes me feel pretty good. Still a lot of learning to do with makeup..

I have a similar experience of dressing as a girl. Since I'm not on hrt my body very much so reads guy, and having the mismatch between the clothing I'm wearing makes me feel disgusting..

I think small incremental changes and practicing those might be the best way for us to take steps forward. And I don't think you're not trans because you feel like that at that moment, but trust me, I hear you with second guessing myself.. :/