I wouldn't panic yet. I think the heat treat is like 400 degrees, you might be able to go to use a heat gun to get up there, or do a deal with a powder coater, or stick the back end in your stove. The other issue is how loaded that area is. Anything out by the drops is at the easy end of the spar. That is why the tubes taper on steel bikes out there, and the triangle comes to a point. I'm not saying you are good to go, but it may be salvageable. One nice thing about 7075 is it does not need all this.