a long distance relationship help?

ive known this girl for a while and i visited the UK and we got closer, ever since then we developed a relationship. i have a good job but i don’t know what to do if i should move back to the UK and change position or should i try get her to come over here, i don’t think that can happen cause of visa issues. this is my first long distance thing.do they ever have a happy ending? how can you keep that fun into the relationship by being so far away? just need some help