How To Treat Swollen Lymph Glands In My Neck?

Hi there I began feeling unwell a few days ago, I ve had aches and pains, a fever and hot and cold sweats. As well as this I had some swollen glands on the left side of my neck. I didn t worry too much about any of this as I ve had glandular fever before and thought it was flaring up again. I just used panadol and ibuprofen. Yesterday morning when I woke up, I had some epigastric tenderness. Since yesterday it has been getting progressively worse, to the point during the night where I thought I was going to have to go to the hospital and was crying in pain. The pain is located in my epigastric region and off to the right under my ribs. This morning I have started vomiting and can not stand up for more than 5 minutes due to the pain. Lying down makes the pain instantly better. I ve tried taking tums and pepto bismol and even pantoprazole (left over in the cupboard - it was my fathers for GORD) but nothing has really helped. I have had an appendectomy and have SVT. I m also on the OCP. Other than that, no medical hx. What could this pain be?