Tightness, Heaviness Below The Rib Cage, Burning Sensation, Muscle Spasms In The Lower Back, On Medicines. Whaqt Could This Be?

I am a very fair skinned female of twenty years living in the northern half of California. I weigh may be 165lbs at 5 2 . I wonder if I possibly have either a stomach ulcer , in the process of one, a parasite/bacterium or may be none if these. I have had tightness and heaviness that I recognize, occasional burning sensations that have spread directly from this 3-4inch area below the edge of my left breast to my back in a 3inch line., seemingly bloated a bit but it s not always after eating and it s not as often as when it flares up at night and peaks usually 3-5am as. This episode has been going on for at least two weeks now. I ve had muscle spasms lower back and in this area but I can t decipher the frequency :(. This has been going off and on since around march of this year or may be earlier this year, I think. I remember when I went for an appointment a few weeks I believe after I noticed for the first time and she thought I had a benign cyst on my spleen from just pressing on and around the area?! When I had the ultrasound the lady never mentioned the area of concern at all on the end results. Could this even be an allergic reaction? I do take the 24hr non drowsy allegra 180mg of fexofenadine HCI one per day since early march.