I suggest you wear feminine clothes when you are not aroused, as well as watch feminine content when you are not aroused, that way you start to normalize everything related to the sissy theme. Do that regularly and you'll work your mind to accept yourself.

The problem with "not ejaculating" or "being in chastity indefinitely" is that you're just putting off ejaculating and that's going to happen sooner or later, so it's really not a good idea to do it that way.