I feel I can't focus on other aspects of life because of my girlfriend but she is doing that very well. Why do I feel that?
Because that maybe true she has her priorities sorted. She is in tune with her realities.
As far as you are concerned, do you wish to spend all your time fantisizing about someone who will leave you for the very same reason? If she sees you would rather live in a world of enchantment rather then try to be a provider she will eventually leave.
No worries first thing, stop thinking about her all the time.
Second set a goal. Something you have wanted to do for a long time like learning guitar getting ripped. Do it, do it now!
Third, set long term goals.
When you have all these things going you will be at par with her. See how your relation changes for good
All the best and fall forward.