The main problem here is that you don't respect your feelings.
Whatever feeling you have, x y or z, there will always be somebody who would feel it more than you in the same situation, and there will always be somebody who would feel it less than you. Your emotions are the definition of you - you cannot disrespect them without making yourself unhappy.
In referring to 'normal', you are looking for an external set of parameters, and asking if you are within them. A rulebook, if you like. There is no external rulebook. There is nothing to refer to. So, we have to make our own rulebook, and everybody's is different.
I suspect that there are many other things he does that make you upset, but you think you might not be 'normal' to feel upset by them, so you pretend you're not. This is also disrespecting your feelings.
How do you feel about being with a partner who breaks things off every 5 minutes? In the pit of your stomach, how does that feel, regardless of any other issues?
With regard to the pants, if you can't get out of the relationship/house immediately, tell him that if he leaves any more for you to clean up, you'll put them in the bin, and make sure you follow through.
How do you think he'll respond if you do that?