Are you going to ask your doc for a prescription for the benzo, or purchase it online?
If you are buying online, look up etizolam. Half life is 4-8 hours, and it kicks in quick orally on a empty stomache or sublingually. It should hit you within minutes. It's about as potent as Xanax, but I think it is less likely to cause a blackout as it is a more mentally clear high. Try to do some searching to find yourself a domestic vendor that sells legit pharmaceutical brand blister packs of etizolam.
You should be able to find blister packs of ten 1mg etizolam pills for under a dollar a pill. If it's still legal or a "grey area" drug in your country, then you may look for international vendors as you won't get in any trouble if on the off chance it gets seized at customs. You'll just get a letter from customs asking you to not import it again. That's why I recommend finding a domestic vendor as it will arrive guarenteed because it doesn't go through customs, and domestically it will show up in the mail in a few business days.
However, you may find them at a much cheaper price internationally, so if you can wait up to 2 weeks for international shipping, and you are certain etizolam is not yet scheduled in your country, it may be worthwhile to order abroad to recieve twice as much for half the price, as domestic vendors for etizolam will have higher prices.
Etizolam is great for panic attacks and bad anxiety because it's effects are quick and like I said, it's more clear headed then Xanax IMO so you will be able to dose a bit higher to increase it's anti anxiety effects without blacking out.
Also, since it has a relatively short half life, you won't build a tolerance as quickly as you would with a long half life benzo like diazepam (Valium) which stays in your blood stream for days because of its 36-200 hour half life. If you avoid taking etizolam every single day and limit it's use too only when you feel a panic attack coming or when your going to be in a public situation where your anxiety becomes unbareable, then you can avoid physical dependence. Benzo withdrawals can be the worst in the world if you have a daily habit and run out. If you do begin using daily, then if you are ever running low in supply, you must do a taper, even just a short one so you avoid withdrawal seizures, and other symptoms which can kill you.
But try to never use daily, take a break on weekends if you need them during the week to be functional at school or work because you have anxiety crippling enough that you really believe you need to dose for any work or school situation. If you do use every week day, use a small dose and don't increase it often. Try just a half mg before work or school, and then maybe another half mg at lunch, 4 or so hours after your morning dose. Don't try to get high from benzos, they aren't really euphoric. I find the dose that works for me well for anxiety isn't actually high enough to impair me at all. I don't feel any effects really from half a mg, but it smooths out my anxiety in the background. I've used the same dose for months, half a mg before work. Sometimes another half a mg for sleep, but I recommend avoiding relying on benzos for sleep.
By at least not using on weekends, and skipping a day here and there during the week, .5-1mg of etizolam has remained an effective dose for anxiety for almost a year for me. Just last week I didn't have any benzos for the whole week, and didn't notice any withdrawals.
Anyways, sorry for the long post. Try etizolam if you haven't, hope you find what you need.