A very typical reaction from our country regarding psychiatric illnesses.
He is stressed out that's for sure. Weather he is suffering from depression
or not depends on various symptoms like how is his sleep, appetite, mood, energy levels, attention concentration etc etc etc......he will need a full psychiatric assessment.
From what you have explained, it seems he will not consult a psychiatrist
The following are the options in no particular order of preference
1. Keep trying to make him see the sense in going for an assessment so that "both of you could be assessed"...make sure that he understands you are suffering as well and may be if he comes there may be something that you may change in how you are etc etc etc....trying anything not to make him think its only him. Keep at it for long and atleast to get rid of your "nagging" he may come once......but I dont see much long term benefit in this.
2. consult a general physician...both of you...who knows and deals with psychiatric problems...that may be more acceptable to your husband
3. ask him if he would be ok to talk to a psychiatrist online....there are expert specialist services available on this site where you can have a psychaitrist consult via chat and that may reduce the stigma even further to your husband.
Keep insisting that it is for both of your assessment...which truly it should be....and then only for an initial assessment
keep talking to him about not just medicines that help but also talking therapies...or better use counselling
rather than therapies word...to make it more palatable to him
Finally, in some countries, there is still a practise of covert administration of medication...i.e giving medicine without someone's knowledge. This will depend on the legalities involved and the best practise of that country.
Hope this helps. Good Luck to both of you.