Gorgeous photo he looks very chilled there considering all of his horrible allergies. I sympathise as I have a dog with allergies (and I too personally suffer with them!) so know only too well what it is like. Not sure what you are feeding him but I stopped all dried food a while back, home cooked food definitely helped. Regular baths also seem to help my girl and I recently purchased some vetbed gold which I put on top of her bed and I have found that pretty good too.
I did go to the vets for help years ago (Maggie is now 11) and never really felt supported, they gave us some Malaseb too.......seems to be there usual first choice but it contains antibacterial and antifungal agents, in my opinion this is not the best treatment for allergies at all. I find natural, sensitive products the best for skin problems caused by allergies and soothing products are also helpful. If the skin is broken colloidal silver can help, just dab a bit on.
Unfortunately a lot is trial and error is needed - you will get there but expect it to take a long time. Also consider keeping a log to see if there are any patterns or triggers. We found that we now have to rinse Maggie's undercarriage, legs and paws after every week all year round.....yes a lot of work but worth it, it makes such a difference to her itching which of course affects her overall comfort.
Good luck and keep up all the excellent work, you will get there in the end
Jackie x