I think the next step is to assess where you are, your needs and desires for you and your son. This may take a little time. By the end of your son's preschool you should be on terra firma. Until it become obvious to you, treat yourself to different experiences and see what brings you joy. My struggle would be to not become a recluse. Your son will certainly help prevent that, he will need stimulation. Perhaps doing things with him is a good short term solution until you are compelled to do things you love. Just a thought.
