Seborrheic dermatitis--PLEASE READ AND HELP

Recently I have had a really bad SD flare up. My scalp starts flaking and is really itchy, and at some points I do get bumps on my scalp that can break open when I scratch them. I am just looking for advice for the flaking/itching--medicine, lotion, shampoos, etc. what do you all use? also, can you put what the active ingredient(s) is also? I have tried head and shoulders, but it does not do the trick for me. I found that the medicated selsun blue (over the counter, active ingredient is selenium sulfide) does provide some relief, but the flaking and itching still persist. when it gets really bad, I use medicated ointment for my skin (ive been diagnosed with eczema and dermatitis since I was young) and massage it into my scalp (i think the active ingredient is betamethasone--I dont have it in front of me so I'm sure I spelled it wrong) Please include any information--I am desperate!!