[Maximo]

Poor Mitsi. Since she has always suffered nervousness about going outside, but the vomiting is a new development, I would not be inclined to attribute it to nerves.

Is the grass eating new or has she always done this?

How long has she been taking the anti-anxiety meds? You wrote that they helped, but is there any correlation with the days she vomits?

Any changes in diet? New food or treats? Change in feeding schedule?

Did anything happen outdoors recently that would make her even more fearful?

I associate yellow foam vomit mostly with hunger. When Teddy was a pup, if he went too long without food, he would vomit yellow foam. This often happened in the morning. When I started giving him a few kibble late at night, it solved the problem.