Thank you, it is nice to relate and follow our individual healing journeys together :) I am glad to see your hard work is also paying off!

The question about Tai Chi is better asked to an expert, but here is my opinion:

I am somewhat reluctant to suggest practicing tai chi from video and without a teacher because there are many intricate corrections and insights that I receive from my teachers that I would never have known otherwise. Also there is risk of building bad habits in terms of my body's structure (akin to bad habits lifting weights that could result in injury later on).

That said I have never tried to learn by video or online and my teacher has tons of youtube videos and I'll share the link with you in case you are interested to peruse them and I think you could get a lot out of these free teachings (they are not in order, so beginning videos are mixed with advanced): https://www.youtube.com/playlist?list=PL0095908C722CF844

If your goals are relaxation, stretching and breathing I suspect that qi gong might be a practice to consider pursuing by video. I am not qualified to say for sure, but I think qi gong might be easier to excel in without a teacher's close eye.

If you are curious to talk to him I could put you in touch and he would have a much more informed answer for you!