About 2 Months Ago I Started Feeling Very Full When

About 2 months ago I started feeling very full when I eat and it feels like the food sits at the top of my stomach. I have taken probiotics, acid reducers, and enzymes. I have stopped taking medications thinking they were counteracting each other. I had an xray and no mass was present. I had an endoscopy and it was normal except for stretching my esophagus. I had cereal this morning and then a normal meal at lunch around 1pm. I haven't had anything else to eat since then and I still feel full from that lunch at 11 pm tonight. I feel a lump at the top right of my stomach which has been there for several weeks. I really am at a loss for what is wrong with me. Can anyone help??