It sounds like you have two problems. One of them is a sleep problem. But there is another problem. Being at your parents' house is fulfilling some need you have. It could be lessening some anxiety. Or it could be that the interaction you have in the evening with your parents helps you to unwind. Or it could be something else.

If you're involved in a relationship, does spending the night with your g.f. help?

I don't think humans evolved to find it normal to be alone at night. But, in Western culture, it's expected that adults should feel okay being alone at night. I'ld say - do whatever is working for you. But you don't want to get it built up in your mind that you have to be at your parents' to sleep. That will tend to become a self-fulfilling prophecy.

I don't think that giving up your apartment is totally good idea. Move home completely, and you may have a heck of a time facing moving out again. It's good for someone your age to have a place of your own, even if you are temporarily not sleeping there.

I have a hunch that you moving home is not totally because of your sleep problem. Give that some thought. There might be something else that you need to work out. Maybe you really don't like the apartment you've been living in. Maybe you are under financial stress. You don't have to explain or justify to anyone doing what you feel is best for you. But moving back home at age 32 is kind of going backwards in life.

Sometimes we fool ourselves about why we are doing something. Have a good long talk with yourself about what is really comforting to you about being at your folk's house.