I used to be a switch then changed to be a sub because I had similar thoughts to you... however, I recently encountered someone more sub than me and my Dom bits woke up a little so I ended up back as a switch...

The labels are artificial and arbitary. There is no such thing as a definition of a 'sub' or 'dom' or even 'switch', no tick box of characteristics that you have to have to qualify for one or the other. Instead there is a continuous variable axis with 'sub' at one end and 'dom' at the other and most people are somewhere in between those two. I always argue that everyone is a switch and we identify as sub or dom in relation to the others we encounter. Those who identify as 'dom' simply rarely encounter anyone who is more dom than they are and so rarely (very rarely in some cases) identify as sub. Those who are sub rarely meet any who are more sub than they are and so rarely identify as dom. Switches are somewhere in the middle and so meet a greater proportion of those who are more and those who are less dominant than they are. They therefore reidentify more often.

Best thing to do is stop worrying about it and play things as you enjoy to play them. Your body will tell you what you enjoy most soon enough.