Husband Stage 4 – brain, lung, adrenal gland – looking for hope

Hello all I am new here,  but have been reading all your posts for the last few months.   Here is our story.   My husband is stage 4 melanoma,  we were diagnosed last August with it in the lungs, brain and adrenal glands.   He is Braf positive and we were on targeted therapy  Debrafenib & Trametinib.  He tolerated the therapy well with minimal side effects.  The tumors in his lungs and adrenal glands were shrinking.  But the brain kept progressing.  We did gamma knife in august for the first 13 spots,  they were stable , but in October 7 more cropped up and we gamma knifed them too,  in December all previous spots in the brain were stable but 6 more cropped up and we did gamma knife again.  in Feb 2018 we did CT scans and the spots in the body were still responding and shrinking .  Which was all good news,  but the follow up MRI  in mid-march now showed 20 new spots in the brain.  The radiation oncologist recommend whole brain radiation , so we did that  and we switched to immunotherapy Keytruda.   We completed whole brain April 16 and started on Keytruda May 16th  .  First follow up MRI on the brain showed for the first time no new spots.  But 30 spots progressed.  We decided to hold on more gamma knife and see if this could be pseudo  progression and see if it will resolve it self. Since he had normal post radiation side effects which were normal .   Recently in the last few days we are noticing some confusion, and walking issues,  our next MRI is scheduled Aug 3rd  and I am worried.  Any encouragement any one can give would be great.