Underbite After High Heat Cook

I went to use my egg last night, and noticed that it had developed a pretty severe underbite.  The last time I used it was over the weekend for a very high heat pizza cook.  About a week or two ago, I replaced the cast iron grate that the lump sits on with a much more open stainless steel grate that allows more air through.  The pizza cook last weekend with the new grate resulted in a roaring fire with flames that were licking the sides of the egg/gasket, and occasionally spitting flares through the vent at the bottom.  Anyway, I'm not sure how this extreme heat could have caused an underbite, so maybe it's not related; nonetheless, I'm thinking of just going back to my normal cast iron grate now.  And the bigger problem is how do I fix the underbite?  I'm putting a call into BGE today, but figured I'd ask here too.  Really bugged about this.  My egg is only a few months old, and I feel like I shouldn't be having this kind of issue.  By the way, also probably worth mentioning that the gasket seems fried in certain areas.  Do those things really only last a few months before they have to be replaced?  That just seems a bit ridiculous.  Anyway, any help anyone can give would be appreciated.