Look at you, you’re someone with an awesome hobby/interest/career, and someone you really dig makes sweet, amazing music. You try, with what little time you have to get up to their level, but after several hours of practicing, you’re barely getting that one part down.
Don’t let this get to you. You already have an interest that excites you, and you picked it up again today. Good on you. Now, all you have to do is do a little bit better than what you did last time.
Keep it up.