Any ideas/support? I'm a nightmare waiting to happen

[InfinitySeven]

I need to lose weight. About two dress sizes, I think.

I tried low-carb, but didn't see much difference. I'm still doing it, but I decided I'd do exercise, too.

Started with the 30 day shred. Made 28 days, then damaged my spine (it's metal) and have been told not to do it again.

Went for runs instead. Tore my knee. It holds up okay, but they don't want me running on it.

Walking is a no-go because I have fibromyalgia, and exhaust quickly. I also work long hours, and don't have time for lots of short walks (or one long one, really).

Tried cycling. Fell off after a grand total of three minutes on the bike, and broke my wrist.

I already eat relatively little. I cut out all junk. I have muesli at mid-day, a breakfast/lunch hybrid, and protein for tea. I'm trying to just drink watered down juice, because I can't stand water.

I'm doing crunches, but they won't be enough on their own.

I can't have my spine fixed until my stomach is in better shape, so what can I do? I really wanted the op before Christmas :(

It sounds to me like you are eating nowhere near enough food. It can't be helping with your various injuries or the fatigue. If you eat significantly less than your TDEE (recommended level is 15-25% less for steady weight loss) then you'll screw up your body chemistry.
I'm doing vibration plate training at the moment because I have postnatal joint problems ruling out running/aerobics etc. Is that an option? It's short workouts involving holding positions (like plank, squat, lunge) on a vibrating plate. It can help with weight loss as it burns about 500 calories, but it's good for toning, muscle strength, bone density. I'm hoping to be able to do something a bit better for cardiovascular fitness soon, though I am walking a lot too, but I've found it helpful in the interim.
Maybe try a different diet approach as well - SW, 5:2?

You need to have breakfast to get your metabolism going for the day. I would calorie count and eat around 1200 a day.

I would stop doing crunches unless you're sure that your technique is really good. If its bad you can train your tummy to stick out. Can you swim? That and a bit of weight training would probably be really good for you. Get one of those big balls and have a go at some exercises using them. Just sitting on one is great for core stability.