If he’s on meds, then your number one suspect is those meds - either wrong ones, or wrong dosage. Try to minimize the number of them, in the first place, and then try to minimize the dosage, in the second place. Psych meds can have horrible effects, especially when wrongly combined.
Second, check his potassium and magnesium levels. Try taking a tablespoon of molasses in a half cup of hot water with the rest milk and see if it helps. Bananas and avocados are also high in potassium. You can get magnesium supplements, get the citrate kind for better absorbtion. These two levels are crucial for anxiety and OC issues. And add a B-complex and K-2 vitamins to help with absorption as well.
Third, try some herbal supplements to see if they are enough. Especially valerian root capsules and chamomile tea for anxiety, and melatonin for sleeping. They are not nearly as strong as pharmaceuticals. Do research, there’s a lot of info out there. The good news is the mildness, it’s hard to make a bad mistake with herbs. If it works, it works, otherwise it just doesn’t work.
I’ve worked with students with these issues, so I know these suggestions can be very helpful. No one size fits all, but these are safe things to try. And tell him to get some physical exercise, too, even if it’s just walking. And drink plenty of water - some people are extremely sensitive to dehydration.
Finally, of course, prayers are offered for you all.
I would like to add to the vitamin suggestions of the post numbered below, also fish oil is very helpful to the brain, because our natural food supply is often deficient in it.