I suggest you start by getting a bra that better supports your breast, and doesn't choke you. This will solve most of the tee shirts problems at least...

Try to increase the colume of cardio workpout, becaue it seems like you're bored with it to death already :-)

Ask at your local gym what you should do to strenghthen your back (don't forget to work on your stomach too to maintain balance). I would also work on the cest muscles so the can hold you better.

I don't see the problem with eating three hours before going to sleep though.