please help black vomiting

You are TOO TIGHT or your band has already slipped!! Like others have said, see your surgeon ASAP,  also ask for an Upper GI...good luck.

Coffee ground vomitus refers to a particular appearance of vomit. Blood contains iron within heme molecules in red blood cells. When this iron has been exposed to gastric acid for some time, it becomes oxidized. This reaction causes the vomitus to look like ground coffee. Coffee-ground vomitus is a classic sign of upper gastro-intestinal bleeding. A peptic ulcer, for example, may bleed into the stomach and produce coffee-ground vomitus. When bright red blood is vomited, this is termed hematemesis. Hematemesis, in contrast to coffee ground vomitus, suggests that upper gastrointestinal bleeding is more acute or more severe, or originates more proximally than the stomach: for example, in the esophagus due to a Mallory-Weiss tear.

Oxidized blood from an upper gastrointestinal bleed can also be excreted in stool. It produces tarry, blackened stools known as melaena.

See more here.
en.wikipedia.org/wiki/Coffee_ground_vomiting

Hey everyone thank you all for your support and your concerns, I saw just got home from the doctors and he told me I just have acid reflux from my band being too tight now I can breathe a sigh of relief thank you Jesus. so he took .5cc out of my band and told me to call him if it happens again and there is nothing to worry about, Thank you guys so much once more for your support.
P.S NSV went to the gym this morning for an hour and I didn't give in to my worries and eat them way me... cause Lord know that I eat when I'm worried or stressed

Are you going to have your band checked for any slippages ?

no he said everything is fine

 glad to hear your on the road to recovery.
good luck and great job going to the gym
wendy