I'm not a Dr. but I would definitely suggest easing back into it - start with short beginner and low impact rides and increase the duration as you feel better. I think your idea of raising the handlebars also makes a lot of sense.
Good luck!I have started PT. I have not started riding yet because there was an issue with the bike not powering on. I replaced the cables. It powers on now but no metrics. Peloton is coming out to fix it today. Hopefully, I can ride this evening or tomorrow morning. Fingers crossed!!!