The Mollz... sounds nearly as cool as The Fonz.
I know the first few days (lasted 5 days for me) on a low-GI diet was tough as; because your body basically goes into detox mode, flushing out the excess stuff you aren't eating anymore (sugar!!). I remember watching a UK programme, Can Fat Teens Hunt, and the first casualty was a girl at the end of the first day crying her eyes out because she had a really nasty sugar crash and she wanted to go home.
I've got a terrible sweet tooth and it took every ounce of willpower I learned and had to not get that Snickers bar at the grocery store checkout when I first started.
Insulin resistance (I think) is a lot more common in overweight/obese people more than we realise. Correct me if I'm wrong, but with insulin resistance, your body's not using the insulin it produces effectively or efficiently and you end up with more glucose in your bloodstream, which is why rates of Type II diabetes in overweight/obese people are skyrocketing. I believe IR is common in women with PCOS who are overweight, but can occur in women who don't have PCOS.
Have you had a skinfold test before? If not, get a personal trainer at the gym you go to do one for you. I swear by skinfolds and get them done every 8 weeks. You get 4 areas pinched with a set of calipers: bicep, tricep, back and hip. The measurements are added up and the total measurements correspond to a body fat percentage. If you're doing a lot of gym work- like lifting weights on a daily basis like me and lots of cardio, but not seeing the scale move too much, it could be that you're putting on muscle.... and muscle weighs more than fat. A caliper test is a **** of a motivator. When you see the fat start coming off this way, rather than a number on the scale which only reflects *weight*, you look at things differently. When I first started lifting, I weighed 93kg. 12 weeks later, I put on 4kg, but lost 30mm of body fat *and* my pants fit better.
What I like about body fat rather than weight is that you can be thin and still be "overweight".
Seriously consider the skinfold. And see if a personal trainer will do up a seasonal programme cycle for you: 4 workouts per year, 3 months per workout, and get a skinfold at the end of every 3 months. If you have to pay them the one time, it's well worth the money. The owner of the gym I go to does this as part of the gym fees. But make sure they show you correct technique for lifting, otherwise, your programme won't be worth the paper its written on.
Can't help you with constipation, but try to add some fibre. If you haven't already, switch to multigrain wholemeal bread, not just brown bread. What about switching meat to beans twice a week (I might have to try this)? Eat the skin on the fruit if you don't already. If you're still constipated after all that, add psyllium fibre to your meals (doesn't add flavour, IIRC) or to your water. Fibre makes you feel full too.
Hope this helps.
Cheers.
Mollz