I'm glad you had some tests done. That's the safe thing to do. It's good to have negative results.
If you think you may have food allergies - or sensitivities - don't cut 2 things at once. Just stop one thing at a time.
Most important is keeping a really good food journal - see many posts, threads using the search box at the top of the page. Write down the date, time, everything you eat, drink, meds, and symptoms or reactions. I like to use a not too small notebook or calendar so I have space. Part of the reason for keeping a journal/log/diary is because some people have reactions as much as 2 days after eating a food trigger. (example: migraines caused by sulfites)
A really good allergist can help. Skin prick testing isn't too bad, but blood testing and others are notoriously unreliable. If you start getting a list of foods causing problems an allergist can advise you about challenge testing. Don't do this by yourself if you have serious reactions. (See the search box.) I get stomach problems and tachycardia reactions.
If you think you might have a problem with gluten (there are at least 100 varieties) consider it might be just a wheat intolerance or allergy or sensitivity (those are different things). A gastroenterologist can take a tiny sample of your small intestine - the only reliable test for celiac.
I have food intolerances and they are easy to deal with. I don't have a problem with milk proteins, just the milk sugar - lactose. Try drinking lactose-free milk, no cheese, no ice cream for a while.
I have problems with bread, but less if it's preservative-free. Possibly 2 things going on, wheat sensitivity and the sulfites in store-bought bread. I can tolerate 2 thin slices of bread from a store that advertises no preservatives or home-made bread. I see my allergist soon and will ask if there's a skin prick for wheat.
I can't drink wine unless it's just a tiny glass of my own home-made with no sulfite added. There are sulfites in grapes, but I tolerate a little.
Let us know how it's going. Best wishes!