I'm a 34F and I manage to get bikinis from the likes of ASDA pretty cheap. You can get bra size swimwear (although if you want better ones you'll probably have to go more expensive) but I just go for bikinis where you buy the tops and bottoms separately. I've bought size 10 bottoms and size 18 tops at the same time before, providing it's a triangle style you can just tie the strings up tighter and your boobs are all covered.
I also recently bought a swimsuit from New Look, from the Kelly Brook range. Got a 14 and it fits, if a tiny bit loose around my belly, but it's double layered and stretchy with built in bust support.
I also have problems with jackets, but I have a winter coat that goes around my breasts and the rest of the time wear them open with a belt to hold them in round my waist and a scarf to keep my chest warm.
The biggest problem I have is with sleeping. I can't sleep on my front because they end up all tender and I can't sleep on my back because they're really heavy. I've slept on my sides for years but also have problems with my hips so I can't stay on one side for long, so I toss and turn a lot in the night. When my hips are particularly bad I wake up every half hour, turn over and go back to sleep. Wish I could sleep on my back or front!