I am sorry for your situation of being abandoned during this time as you are expecting a baby.
I know that us moms worry about everything....I worried about having had a few drinks in me the night I conceived so I do know where you are coming from!!
Okay....as far as the meds your hubby is on I am one that believes that everything one is on that affects the cells within a body will affect the egg and sperm as well.....however there are certain meds that are less of a problem than others. The best source of alleviating your fears would be your ob/gyn and perhaps your husband's pdoc. I really think that your worries would be minimal for there are only a few meds men are on that are cautioned most of which are chemotherapy in which they harvest the sperm specifically in that situation for future pregnancies.
For the most part it would be more important what the mom is on in terms of meds since she is the incubator and anything in the blood that nourishes the baby will affect the growing fetus. So I think that you really don't have much to worry about.
As far as hubby taking off.....has he been taking his meds??? I know with somebody who is Bipolar any significant changes can trigger the disorder so perhaps the pregnancy and some of his personal concerns of being a good enough father may have triggered this reaction in him. I have two teenaged daughters who are being evaluated for Bipolar and they have certainly done their share of running away!!!

And since coming here I read about alot of adults doing the same. So I would guess that either he is not taking his meds OR that something has triggered him to act in such a way.
Anyway.....you take care of yourself and try not to worry too much about the meds your hubby has been on....I am sure that when you discuss it with your doctor that they will reassure you that there isn't much to worry about.
Good luck and congratulations ~ Goody