Girlfriend moving away but I have a well paid job here

My girlfriend is moving away for a perfect job however I also have the perfect job here where I will be forced to move if I want to stay with her as the distance is too long to remain in a fully committed relationship. I get paid over 40k per year however if I move I will be looking at a more than half wage per year decrease and I'm not sure how I would feel about that until I moved! She will be on a decent wage there but I still feel like I'll be missing out on my good job here and doing what I want to do - it feels like I'm having to make the bigger sacrifice and she says she doesn't want to move if I won't but at the same time I want her to have the opportunity to further her career should I not move. Really stuck on what to do and it feels like I'm being forced to make the decision rather than wanting to make the decision for myself. I have all my friends here and to make a fresh start without my family here I'm not sure if I'd feel isolated and I've never lived away from home or with my girlfriend. It's a big step and I'm not sure if it's too big, could anyone help me please?

How long have you both been dating for?

I don't think you should move as of yet(i'm not saying you can't sacrifice for her). Both of you should spend the time being separately focusing on what's most important for yourselves( let her go get the perfect job on the other side) while you focus on the good job you got here. However, after about 3-6months, both of you can then see how to see how to make things work much better. Either of you can travel to see each other.