Hi, I've not read whole thread, so I have no idea what your weight is (please don't say if you don't want to), but a mini trampoline, or rebounder as they are called, is a great idea.
Make sure you buy one that can support your weight.
Make sure it has six legs.
A rebounder puts much less stress on your body, and it (amazingly) works your whole body.
You don't jump as such, you just get on it and lift your heels to create a gentle bounce without losing contact with the material below your feet.
You can get rebounders that also come with a handle.
So if you feel insecure, you can just rest your hand(s) on it to give you confidence and stability if you need it.
Start off small and build the time spent on it as much at a time as you feel comfortable with.
Aim to get to at least twenty minutes.
I do it either to music, or the tv, it makes it more enjoyable, and if the tv programme is a half hour sit com, that time will have gone just like that.
The bonus is, once you've achieved your basic twenty minutes, is that any extra minutes will result in your body still burning even after you've stopped.
I can definitely say it's good for me, as I used to jog, but it wasn't good for my spine, as it's a hard unrelenting surface.
Rebounding is much softer, and better benefits.
You can get ones that the legs fold in, so you can slot it behind the sofa eg, when it's not in use.
It's also pretty light, so you could take it through to the back garden if you have one, so you'll get the benefit of fresh air.
I do recommend you get a supportive bra, as I find it's not a pleasant sensation to have ones bosom bouncing around 😱
Wishing you the best of luck in your endeavours.
I'm sure all us mumsnetters are cheering you on to success Yay!!!!