What can I do to strengthen my LES?

I have GERD aka acid reflux disease. I've had this since I was a very small child. I was very skinny as a kid, now I could stand to lose about 40 lbs. However, the doctor basically said to lose 40 lbs and that would cure it, and to continue nexium. Well, I got mad about that, because I've had it for as far back as I can remember, even when I was in the military. (I was skinny then) Now, it has made my esophagus sore, and there is nothing I can do about it. No, nexium doesn't help. Diet changes do not help. I can feel cold liquid come up my esophagus after I'm done drinking even when I stand up! Not a lot, but enough! Especially milk! No doctor will help me! I've tried. I've even changed my diet. My question is, if I start doing sit ups everyday, will that cure it? I need a cure! Thanks! Lets put it this way, I can push liquids/foods up just with my diaphram while standing up. (gross, I know, but true) I've asked about surgery, but nononono, it is diet all diet. blah blah blah..

I know I should have went in to the doc earlier, but I never had any pain associated with it, so I didn't think it was anything to worry about. I didn't get educated on GERD until it started getting worse and painful.

There is nothing "physically" that you can do to strengthen your LES. The only way to correct it is with surgery...a LAP NISSEN (laparascopic nissen fundoplication procedure). If you have only seen an internist, SEE A GENERAL SURGEON instead. If you've already seen a surgeon, get a second opinion. Since you've had GERD issues since you were young, you've probably done significant damage to your esophagus already. Any further damage could result in CA (cancer of the esophagus). Don't give up until YOU are satisfied!!!! It's your health!!!!!!!!