Pentasa depletes folic acid.

X will affect the brain's ability to make serotonin. This side effect causes many problems with X users. Some articles say it may be permanent.

Speed (Meth) and cocaine affect the blood vessels and heart.
If you are not using these anymore, you might have recovered.
But they can cause multi-infarcts in small arteries depending on the person.

Nitrous oxide may impair methylation chemistry...the only way to test for this is to have a MMA test. Your B12 is marginal. No way to know if it is coming down or going up with a single test.
Folate in food also has to be methylated to its active form.

When people use multiple drugs recreationally, there is a trade off chemically in the body. This varies so much from person to person, that it is hard to predict. Also multiple drug users do not eat well. They lose their appetite, and eat junk food commonly.

People with inflamed intestines also do not absorb nutrients well. This leads to a mess...many nutrients may be lacking in your body because of this. Medical doctors do not routinely address this problem.

You might find some help from a holistic MD, a good one who is affiliated with a teaching hospital.