Well I did some british DPM (and there are only two DPM, Desert and non-desert, there was no special uniform for Northern Ireland). I started with the english uniform (Vallejo) as a base. Then added russian green (Vallejo) for the green, I tried to pain it in horizontal lines. Brown was Hull brown or flat brown (always valeljo), then I added black and put some higlight with Khaki on the English Uniform area. I think your main error was to have put too much green, while it is scale-reasonable, it will simply ruin your effect. Leave more Egnlish uniform area exposed, and pain the camouflage lines smaller, now they looks more like blotches than lines and thus disrupt the DPM appearance.
My two pennies of course.