I'm no expert, but it seems to me that if you feel better about yourself when you do something about it, then it is more than an obsession; it is part of who you are.
If people feel better when they cross-dress or when they start HRT, or when they transition fully, then what they were feeling was real. I have felt the same kind of doubts that you describe. I wondered if I was just obsessing or if I was just a pervert or something. But, when I cross-dressed, I felt good about myself. Now that I have been here on Susan's Place for a while and have in effect come out to myself, owning the fact that I am at least a bit transgender, I feel a great deal of relief.
Perhaps enough relief that I may not have to do any more about it. We'll see... The point is that sometimes this stuff can be really subtle. You might have to dig a bit to see what is real for you.