I had this exact same problem. I have also put on a heap of weight too, and I am normally quite slim. For me, there was absolutely no solution. The bloating was accompanied with indigestion and later on heaps of morning sickness (without throwing up). I just always felt like my food had never finished digesting. I would eat dinner and wake up still being able to feel it all undigested in my stomach the next day. Eating oranges and anything else citris helped.
I could not for a second hide the fact that I was pregnant due to this. All I can say is by the time that the morning sickness went away about 14-16 weeks, the bloating did as well, and although I was bigger than when I was bloated I felt a lot thinner and attractive. I feel great now at 21 weeks.
I would buy a belly belt and belly band asap. I refused to do this until too late because the thought of walking around with my zip undone made me feel even more disgusting, but when I actually tried them out I regretted not doing it a lot sooner because I looked so much better than in clothes that were too big for me.