I might be incorrect in my take on all of this, and you would know better than us, but I don’t see him as this evil, abuser that needs therapy. It isn’t totally uncommon for people to feel it isn’t necessary to wait all 6 weeks postpartum, even here on the forums in the past I have seen in the past women that say they do not follow/agree with the 6 week postpartum guideline. People have sex when they are sick. I don’t know the situations in the past (if you told him you could not do it for health reasons and he pressured you anyways, or if he suggested it and you did not say no, or maybe did not feel it would be something you could not do for health reasons)… Maybe he is being selfish but without realizing the effects, maybe just imprudent, I don’t know…Technically, not being in the mood isn’t a good reason to say no to someone to begin with (I know, counter-cultural).
It sounds like he is not choosing the alternatives that society pushes on guys (sexual activity with or without wife climaxing outside of intercourse). That is how a lot of people would solve this problem (grave matter that offends God, but don’t have to worry about dealing with abstinence…)
Anyway, I think you have the correct approach. Make sure it is 100% clear that you will adhere to your doctor’s guidelines because you need to do it for your health. Let him know that you love him and that you know it can be tough on him and ask him if there is any (moral) way you can help him cope with this. The couch can be an alternative for difficult nights. Let him know you love him, but for those weeks, and until your doctor says otherwise, you will not be able to participate in the marital embrace. I think it is very important to talk about it beforehand so it is clear to him, as he may think the Dr’s are exaggerating with the timeframe, and he could even believe that you may feel similarly (once again… I don’t know your situation, but it is a possibility!)
I commend you for taking your responsibilities as a spouse seriously (counter-cultural!), and I think it is very considerate of you to be asking this question on how to help your spouse.