I am so sorry your son had to deal with this. The behavior is not acceptable. I am happy to see you are planning to pull him from the toxic situation.
What are the things that you need to do to decompress? Are they activities that you and your DS can do in parallel? For example, if reading is your decompression time, then set aside a time period to read everyday, then afterward, talk about what you just read. Or if you need physical activity, then is there something you can do together? For example, can you both go swimming or hiking or take a yoga class together? Or if you paint, is there an art thing he can do at the same time?
Communication and boundaries are your friend. You will have to make adjustments. Make sure to check in frequently to see if things are working for both of you and if not, what needs to change.
Does your DS also need a lot of down time? Mine loves his block of time to pursue his interest. He insists it stays as part of our schedule.
Online classes definitely open blocks of time for you.
