Contact the doctor who gave you your current prescription, explain the situation, and ask for a new prescription until you can get a psychiatrist. Stopping this drug abruptly isn't a good idea, so explain this as well when you contact your old doc. Meanwhile, welcome to Texas. This is what happens when you move to Texas, so expect to have to fight tooth and nail for everything unless you're quite rich or well connected. As for magnesium supplementation as suggested above, remember not to take magnesium at the same time you take your other meds -- they use the same pathway into the brain and interfere with each other's absorption. From personal experience, magnesium is often good for relaxing muscles, and antidepressants can often cause muscle problems because it interferes with the absorption of magnesium, as does the overuse of calcium or high calcium low magnesium foods such as dairy, but it's probably not going to be strong enough to overcome a lack of a benzo. If you should run out of Ativan, there are herbs, however, that target the same neurotransmitter (GABA) as Ativan, and they might temporarily give you some relief. Some examples are kava, valerian, and passionflower. Holy Basil is also a good adaptogen to limit your cortisol releases from your adrenals, and might help as well. But you don't want to quit Ativan like this if even if you wanted to stop it, which you don't, so your former doc should be amenable to listening to your temporary needs. Good luck.
It is a shame that everywhere you go they treat you the same way. I have had similar situations and frankly it makes me very angry. I am sorry you haven't found the help that you deserve. The world is a mess..the fact that there is many drug addicts they just assume everyone is a user. I had panic attacks for years and went to group therapy which helped me a lot. I would go to your local Emergency Room and hope for a good Dr. on call that can at least direct you to therapy for your situation. The more stressed you are the more Magnesium you lose out of your system which can cause fast heart beats and migraines. I would suggest that you take 2 cups of Epsom salt and put this in your bath water to help you relax and let your body absorb some of the magnesium that is in Epsom salt into your body for about 20 minutes. I also recommend deep breathing exercises as in example: breath in through your nose and count to ten and then breath out through your mouth and count to ten this will help slow down your heart rate. Best of luck to you. Just know your not alone and the world can be cruel sometimes Take care:)