Okay basically I was with my girlfriend from college through 5years of military service (still going) I had a baby boy with her almost 2yrs ago we argued frequently mostly it was about me being away a lot of the time and I never got on with her parents at all and she was very close to them so that didn't help any.

She split up with me 2weeks ago saying she needed time then a few days ago said she didn't want a relationship anymore however she still sleeps with me when I'm home but says I should look for someone else I know she has no one else and I have to see her when I'm home for my son I really need her is there ever going to be another chance? I've told her id change anything she didn't like.
I think its partly because her parents were so pleased when they heard that she doesn't want to go back to square one (wishful thinking maybe:p )

Whether your in an official relationship, or not, you are tied to her through your child, so be a good father. I suspect, the fact your not there often enough for her, has soured this personal relationship, as it's long distance love at best. Sorry guy, you need to make a choice here about your life, and basically leave hers alone. I think she needs more, than you can give, and it won't be long until she gets it, and your officially out. You must act responsibly, both of you, for your child, so getting along is the priority, not getting her back.

But surely if I was to leave my career in the military this would resolve any issues we had I pay most of her bills she would basically be homeless if I cut myself off from her,
My son isn't an issue I spend every day I have spare with him he'll never go wanting I duno if I'm trying to convince myself she needs me because of how much I need her don't you think she would come around if I was there all the time?

I honestly don't know. Should you sacrifice a career for this relationship? I don't know that either. But what I would do in your shoes, is take it as she has said, set up child support, and she can pay her own way. Discuss this arrangement with her, as its very unfair to support someone who can't support you. The bottom line is communicate, to come to some sort of plan that is fair to you both, at this stage in the game. If not then the court will set the rules. Its debatable whether your presence, on a daily basis, can make a difference, it may be worse, but a topic to discuss with her. I would set the lines of communications first, and worry about all else latter.

For the benefit of anyone who reads this... I was completely wrong I gave up my career and we gave our relationship another go it then crumbled to nothing. Im now a lot happier without her but gutted I gave up my career

Sorry to hear that things didn't work out, I hope you are still doing right by your son