You don't say how long you two have been going out for, or how old either of you are.
"I was working in the UK and wasn't there for her" she says. There are many ways to be "there" so does this mean that you rarely said " I love you" , " I miss you" held it together, telephoned her often, shared your daily lives together?
Long distance is hard and requires a lot of work, not just work requires work.
You need to ask yourself that question were you there?
If you feel that maybe you have some blame there. Tell her. Buy her some flowers when you see her, hug her and say, "say nothing".. Just hug her and see what happens.