I am a wonderful person, I do not understand why I am single

You said it leads to YOUR disgust and disengagement, which means it's a mental issue on your part, not the girls.

No amount of good grooming, height, personality, looks and hobbies will fix your approach to the situation.

You need to be ready to be in a relationship yourself. If you aren't, and you disengage easily, then so does the woman. Women aren't stupid and they won't stay with you just because you're good looking (as @gato said), you need to actively show them that you love them and you WILL stay with them because of who THEY are and not because who you are.