Why do I have frequent hunger spells?

[xMomokax]

Okay so! Two months ago I've been diagnosed with chronic gastritis. Before that, I've had three ER-visit worthy episodes of severe upper abdominal pain (the first happened a day after I ate too much of really cold ice cream, that night felt like I was being burnt from the inside and I had a fever; the second two weeks later after a large burger, and the third after hot spicy noodles and then I had milk. I have stupid food choices when food craving I know). After the diagnosis (concluded through an endoscopy with a biopsy sample; I was Pylorii free) I've been mostly fine, but recently I've had persistent HUNGER SPELLS. For a few days, I couldn't eat normal sized meals but now even if I do, I feel this strange hungry sensation in my stomach like five minutes later. It doesn't hurt, I don't shake or have nausea (I had nausea for a week after meals before this started). My stomach doesn't hurt anymore, though I do have a weird pressure-y and itchy feeling on my back. I have lost 2-3 kilogram of weight back in September (I didn't eat well half of August because of tummy pain so I think that's how I lost it?) I hope someone can figure this out :( I'm scheduled for an upper-abdominal MRI next week (one doctor suggested I do that too just in case).
P.S. I'm also mostly constipated (irregular stools, sometimes normal, sometimes floating, usually normally coloured)