Speak to your midwife about it, have a chat about your current diet and portion sizes and look at the rate you've put the weight on to see if it's reasonable for you to cut down a bit without affecting your baby's growth.
I started pregnancy as a larger woman and have managed not to put on much over all (32 weeks) so far, though I did lose some earlier on with morning sickness and I've since put it back on again and am round about my booking in weight. So, on the one hand, huge amounts of weight gain aren't necessary in pregnant if you are already overweight, but its also important that you are well nourished whilst growing your baby so in your situation (and mine) I'd be looking at trying to maintain your current weight and/or slowly put on weight in line with baby's growth rather than trying to lose weight now.
I understand that you are upset about the changes in your body, and are worried about how you can get back to your 'normal' after birth. But please don't describe your body as 'awful', 'huge', 'flabby' at your weight. Other women have bodies that weigh the same (or larger) than yours, and whilst your comments are about self-hatred and self-shame, it adds to the fat/weight shame out there for women.
Your body is pregnant, it's growing a whole new human being, it's awesome, and yes it does look different to how it used to and of course once your pregnancy is over you can focus on getting your body back to a shape you are comfortable with but try not to beat yourself (and unwittingly other women) up because you've put on weight during pregnancy, most women do. How much varies wildly due to sickness levels, nausea, starting weight, cravings, baby, etc.
I'm 17st 4lbs this morning (32 weeks) - I was the same weight at booking in - though that was a bit high because of Christmas, I'd previously been below 17st - but have put on weight since my sickness aided 16st 7lbs mid pregnancy. In January 2011 I was 22 st 10lbs. So you might see my current weight as unacceptably high, I see it as quite good progress on a long journey to improve my relationship with food and exercise where I'm currently at a midbreak enforced by pregnancy. Its totally relative.
I do realise you didn't mean to critcise my weight, or that of other larger women but it does all add to the noise that larger bodies are 'awful' and shameful.
In short, give yourself (and the rest of us) a break, you're (we're) pregnant, a chunk of that number on the scale doesn't even belong to you (us). You wouldn't weigh yourself when holding your newborn baby and complain about your joint weight. If you aren't convinced that you are eating a healthy diet in pregnancy, then speak to your midwife about safe gentle changes to make to minimise weight gain in the rest of your pregnancy.
If you're feeling really anxious about how you'll lose weight afterwards, then you can get advice from your GP/referred to a nutrionist. It's totally possible to lose weight from changes to diet alone (it's how I did it as I have difficulty getting out to exercise) though obviously it might happen quicker if you make changes to make your lifestyle more active.
Apologies for the length and tone of this. I hate that women are made to feel bad about their bodies 
especially when they are pregnant/new mums 
. I get that you need to feel comfortable in your skin (I made the decision to change my lifestyle, and so lose weight too) but you can't do it by makiing yourself feel bad about putting on pregnancy weight.
All the best xx