Zoom whitening chemical burns on my gums. How long until it heals? (photos)

I had zoom teeth whitening a week ago. Some of the bleach get on my gums and caused whitening on those spots. The first couple days following the whitening the gums swelled and then some dead tissue peeled off. Now a week later they are still white, throbbing, and purple in spots. Ive been applying vitamin E and gargling with warm sea salt water everyday and a couple times a day. Im wondering how long until this clears up? I'm concerned it's taken a week and still looks like this.