little.miss.worry, sounds as if u have completely standard IBS. I have it too and have for the last year. Comes and goes but I have noticed that it was worse after a bowl of cereal, so I cut out milk and i didnt get as nauseous. also spices and garlic can make me bloat up and cramp. its all about listening to what ur body is telling u it doesnt like. or its just anxiety sadly.
best thing I found is buscopan, £3 for 20 tablets in any supermarket or boots/superdrug. when im really badly bloated exercise can help, i feel as if my muscles just forget how to work but if i go for a walk or run or anything that 'jolts' my belly its like it will slowly wake up. theres some colonic massage stuff ive found on youtube before which might be worth searching for, or a hot water bottle as someone else also mentioned.
lying on ur back with ur legs straight out, bring one knee tightly to ur chest, and then the other side, thats meant to help release air, or the yoga pose that works for me is lying on ur front, keep ur hips on the floor but push ur chest up so ur arms are straight and ur looking at the ceiling stretching ur belly as much as u can.
the other over-the-counter meds u could try is copamine, peppermint oil tablets that go to ur bowel to work, my cousin said they were the only thing that worked, but i didnt see a big difference. all trial and error.
Good luck!