If you're certain of that, try to get her proper help for it. Dealing with stuff like that without it is exhausting, and burn-outs as a consequence of that aren't much fun either.
Also, back on the topic of models and such. Do you have your stuff in its own room/space? Especially the place you paint new models could easily become a trigger if that happens to be say the kitchen table and models and paint slowly start taking it over. So if you can give it it's own place, and then make sure the models don't leave that place, that will help alot with this sorta stuff.
That at least isn't too difficult to solve, assuming that's all there is to it.
Does she like the miniatures, if so you could try to involve her (a bit) into it, let her paint her favorite models from your stuff that sorta thing. Also what's SCA?
Other than that, it's mostly just stating the Obvious, spend more time with her and such.
And possibly look into couples therapy and such. Might also make the step for seeking help with the suspected claustrophobia easier.