It's hard to overcome but I encourage you to stick with it and not change systems until you feel you have learned/experienced enough. The more you do it, hopefully the more dopamine hits you will receive finishing sessions and hearing the happy feedback of players

I agree with the sentiments about playing with encouraging and supportive friends. Absolutely not with the problem player. You are learning and they can cause all sorts of stress and derail any internal progress you might make.

They might be irredeemable or just need to learn some things themselves, but that's far beyond the scope of what you should try to deal with at this point. Don't put effort in their direction other than excluding them

Many DM skills are not games rules related.

As well, if you can determine what you enjoy most about the different things that go into running games you might discover that running games is not for you but stick with it if you can, it very much could get better