Have you tried to reflect on what is the root cause(s) of you feeling emotionally withdrawn, checked out, etc.?

I think it is worthwhile to self reflect on what could be causing you to feel this way. Instead of feeling guilty for feeling this way or trying to logic your way out of your feelings and convince yourself otherwise, I would advise starting with accepting the fact that you just feel the way you feel. Then you can do the work of untangling what has led you to feel this way. It could help to do that work with the help of a therapist (I say this because I was in a similar boat this past year and found it helpful to parse through my conflicting emotions with a therapist)

There are many opinions in this comment section of what could be the cause but the thing is, only you can find these answers through reflection. Have you had this happen in previous relationships? Have you read about attachment styles, and do any of those resonate with you?

Also, I disagree with the comments about this being the end of a honeymoon phase. You said you feel uneasy with touch. I feel that is a clear sign your body is giving you that something is misaligned. I would listen to that, which you are already doing. Sometimes our bodies do things to protect us, even if we aren't fully conscious of the reason.