I understand what you're feeling andy_pap. I'm sure many of us have been there. Knowing this just isn't right, but not what to do about it.
I will also say, in reference to earlier posts, that looking for causes, such as, 'I played with a girl once', or 'I think girl's clothes are nice', blind alley. You are what you are. I have watched a number of kids, from babies to adults. I can tell you now, looking at a child even under 2 years, you are looking at the adult. Human personality is part of what we are. That includes this problem.
As for what you do next, since you are in the UK, I suggest you keep coming here, but also look out for TG groups in your area. With respect to Americans, here people tend to only start seeing therapists when they have made up their minds to pursue a particular goal.