Thanx alot is ot a sign of gluten sensitive enteropathy
Consider trying to cut out certain food groups for several weeks - one at a time - and see if you find any changes. Gluten (wheat, rye and barley) is one specific food group that's known to cause gas, depression, fatigue, brain fog, etc. in many individuals. You might want to start with that one first and if no change is noted, consider dairy. For more info on what wheat might do, check out the book Wheat Belly - fascinating reading.