My husband has anxiety and depression which is partly inherited and partly because his youth was violent and generally crap.
(I have written about him on here before)
It is difficult to separate the condition from the man being a shit human being. Believe me, we have come very close to splitting up on tons of occasions because he takes his victimhood too far.
Symptoms of anxiety and depression overlap, but here is what I understand them to be.
A sense of failure, hopelessness, fear, and never being good enough.
Asking repeated questions on the same worries over and over again until you want to scream.
Insomnia, or sleeping too much.
Eating too little, or too much.
Not being able to get out of bed, or a general feeling of tiredness and weakness.
Physical symptoms also include pain, interrupted bowel movements, lack of sexual desire, impotence.
Being reclusive and not wanting to communicate.
Pretty much everything else your husband is doing is an excuse to duck responsibility.
He cannot blame you for being depressed. It's not your fault. He may be feeling inadequate but it's not your fault. Trying to have an affair has nothing to do with depression, he was being a shit human being. If he's in bed and cannot move, it's depression. If he's in bed playing with his phone or reading, he's mugging you off. I identify with the two-faced behaviour, my DH was the same. I's just a mask. Depressed people find it difficult to express themselves effectively and often lash out to those closest to them.
My husband was referred to Talking Therapies in the end. He's still quite bad but he doesn't treat me like crap anymore. Is individual or couples counselling an option for you? Though you don't have MH issues, you still need support.