Here is an important tip about your Imigram injections. You can use much less and still stop your attacks. https://clusterbusters.org/forums/topic/2446-extending-imitrex/ For shadows, many people find that ginger helps. You can take it in capsules, or brew tea, or eat ginger candy or drink (non-alcoholic) ginger beer.
Given what you have said, I can't see why you wouldn't try Emgality.
However, we have a lot of experience here that when people say they have "tried" things, very often they have not tried them in the most effective way. Often, for example, they are prescribed wrong. With verapamil, for example (which you don't list but which I assume you must have tried), an effective dose might have to be 960mg or higher, and very few doctors prescribe at that level. From what I have seen, lithium and verapamil can be effective (with side effects) when they are prescribed at the right levels.
The same rule is true for non-prescription items. People often say here that they have tried psychedelics, but they haven't done that according to the most reliable protocol -- every five days, at a high enough dose, with no "blockers" such as triptans. I'm not saying that you didn't do busting correctly or you didn't do the full vitamin D3 regimen correctly -- I have no way of knowing. But because those things are very helpful for most people, I am just suggesting that you be sure you did them right.
Since you say you have tried "everything," I'm not going to start suggesting things just because they are not on your list. I think ketamine is more commonly used these days than it used to be, so maybe that's new enough to mention, and some people report getting relief from nerve blocks. There probably are other "newer" things that I haven't thought of.