I would say carry on doing what you are doing, have you tried a different position for the baby (ie rugby ball hold or lying on a bed). Mine only went down after changing position and lots of massage and hot flannels. Good luck.
I suffer with these. I put a heat patch on my bra all day. Massage before and during feed. Only feed from that side (express other side) and express after to completely empty. Try position baby's chin where the block is. Then in the evening a have a hot bath, kneel down, dangle and massage (hard) then hand express and repeat until I can't do it anymore. This is the only way I've been able to clear it quickly and it bloody hurts. Hope it clears for you
I was on the phone to LLL about pretty much the same problem yesterday morning! One thing I was told that it was important to get heat on before a feed.
She also warned me it could take a while and that i just really needed to persist with all the different techniques. To my relief it cleared less than 24 hours after the first symptoms appeared. Hope it clears quickly for you too.