Lump in throat sensation/trouble swallowing?

I've had a lump in my throat sensation/throat feeling tight/dysphagia/slow swallowing off/on for 5 months now. I did a Barrium Swallow test and everything turmed out fine. I also had an endoscopy done and still nothing found in my throat. Then the doctors said it might be from GERD (acid reflux). They said try different antacids to treat it. I did that and it helped very little. A few months ago I lost 11 lbs. from 80 lbs. to 69 lbs. cuz I didn't a lot cuz of dysphagia. Then a month ago I was starting to eat better until now. But it is still slow in swallowing. I am 17 and a half yrs old and diagnosed with Duchenne's Muscular Dystrophy (DMD) since the age of 5. Other than that I am totally healthy. Also lately I fall asleep all of a sudden for no reason. I feel sleepy off/on throughout the day. I get kinda light headed sometimes/extra beats/nauseous/anxiety/etc. Before my throat problem, I drank more fluids. Now I drink 1 glass the whole day. Do u think its from not drinking enough that I get these symptoms. I am sort of worried.