Hi Heidi,
I suffer from ongoing suicidal ideation and bouts of deep depression so thankfully I have 2 of the most diligent, caring, and entertaining Mutt and Jeff doggies I could ever ask for. However, I am not a fan of exercise but I am a walker that has a tendency to dissociate and can easily end up doing the crying thing too if I don't stay grounded. I use my dogs to talk to and stay focused on where I am and feeling the ground beneath my feet. I love to go at my favorite time of the day :) when it's cool, quiet, and I feel like I can breathe.
I think you have some great ideas going. If riding a bike is the thing for you that's great!
I think the important thing is that you do what you feel like you can without feeling like more than is reasonable but is still a goal to reach for, not an "all or nothing". You are not alone with these symptoms, that is what they are, each one can be dealt with individually, at least that's how I'm looking at them. I try to not look at it as whole, it's way too much.
peace and
light
Rain