Sorry to hear about your struggles.  I have PCOS also and type 1.5 diabetes for 25 years.  I had RNY in September and am doing very well.  Off a LOT of oral meds for diabetes, but still use metformin (1000 daily vs. 2000 daily before surgery).  I use less insulin now also.  I'm down about 42 pounds.

There are a few things I want to say to you.  First, you need an endocrinologist - like NOW.  You could really benefit from working with someone who understands the dynamics of your disease, cravings, etc.  These things are all colliding in your body and you are not doing yourself any favors by just getting a prescription from your OB/GYN for metformin.  You are likely going to need the consultation and approval of an endocrinologist prior to bariatric surgery.  If that isn't one of the approvals you need, I'd question your surgery team.

I don't know how far you are in the process, but you'll need lots of approvals and screenings to get bariatric surgery.  You'll also need a psychological evaluation.  I am sure you will hear much more from them about your PMDD and carb addiction.  It's not uncommon.

Secondly, and I know this is going to sound harsh, but your denial is killing you.  You need to start testing yourself, keeping records and getting on a medication regime that is actually working for you.  Again, this is where the endocrinologist comes in.  Your carb cravings are completely tied up in your uncontrolled blood sugar.  You do realize that, right?!  The higher your blood sugar goes, the more you are going to crave carbs because your body is dumping sugar like mad.  This is a never-ending cycle if you don't get it managed right away.  I am clearly not a physician, but it sounds to me like you need insulin.

Get aggressive about your own health today. 

It might help if you explain what LGBT stands for...

Laparoscopic Gastric Banding [something with a T]?

Laparoscopic Gastric Bypass [something with a T]?

Long-limb Gastric Bypass [something with a T]?

Lovely Girls and Boys who Tapdance?

 I did not experience ANY of the complications listed for the DS.  I had a little acid reflux before surgery--after ward, I had a little as well.  In fact, I realized early on that I needed a stronger med for it (the reflux made me nauseous and I was on pepcid in the hospital)  So I changed to Prilosec--I started taking it 2 times a day at week 2  and it was gone!  and now at week four I forget to take it all the time because I feel fine--then about a day or two after not taking it I feel it coming back a little and pop one and it's gone again.  The surgeon said that his patients (all bariatric patients) go on some type of acid reducer for the first 6 months or so because it's likely to be a problem (with ANY of the surgeries).  I have had no diarrhea, no real gas (less than before surgery actually), and my bowel movements have been relatively solid or soft-serve.  I'm finding now this week, that I must up my fat content because I haven't had a movement in 4 days.  Last time I had lots of butter seemed to get me going but this week I've had very little appetite.  

With the DS, you won't find yourself feeling like you're going to throw up after eating (it's not a common side effect).  What you'll find is that you'll feel full after a bite during your recovery.  Now that I'm four weeks out, I can eat several bites, but if i eat them too quickly, I start feeling like I was just at at Thanksgiving feast and can feel that food in the back of my throat.  So, even if i can take 5 bites, I have to eat them waiting a few minutes before the next bite.  But I haven't felt sick to my stomach at all.  Now directly after surgery it's not uncommon to feel nauseous.  However, this is common with all of the weight loss surgeries and can usually be fixed by taking something like Zofran on a regular basis until it passes.  

What part of the list of DS complications are you worried most about?  If it's the vitamin thing, yes, you'll HAVE to supplement in order to get enough vitamins, calcium, iron, etc. because of the poor absorption.  The vites seem to cost most people between $60 and $110 a month.  It varied depending on where you get your vitamins and what your lab results look like. But, RNY patients are also supposed to take lots of vitamins and many don't--which leads to lots of complications down the road.  DS patients are know for being very medication and vitamin compliant.  Any diarrhea that a DS patient experiences can usually be avoided by using the process of elimination to figure out which foods trigger it--usually it's sugar or other carbs but I have no problem with carbs at this point (though I try and avoid them since I'm not far out from surgery and since I'm already a Type II diabetic).  Gas can also be controlled through diet.  Give me a list of some of the things you're worried about with the DS?

 yes, I am sure there's always a chance of it returning.  I think even with cancer patients they have to go at least 5 years before they are considered 'cured' and often times it still comes back.  good luck...I hope you stay in remission for life :)

 Yes, I know negative reinforcement will not work on me so that is a concern if I go the RNY route.  I have 2 friends who did the RNY which is why I was looking into it first.  Both of them had to keep going back in to reopen the stoma which is not something I want to deal with either.
I'm sure the insurance will find something to fight me on lol, but yea I am grateful the insurance part will be the least of my worries.