To get you to that appointment, I only have a few tips:

1. Healthy living (i.e. working out, eating right, staying hydrated and getting sleep).

2. Find a hobby to do on your free time, something that puts you in some form of peace.

3. During a panic attack breathe with your stomach. Inhale and count to 4, hold it for 4 and exhale for 4. Keep doing it until you think you're okay.

4. Before going to sleep, lay in bed and tense and loosen your muscles a few times in different areas of your body. Do it a few times.

5. If you ever get to a point where you really need to talk to someone and you'd prefer it to be someone you don't know, call 1-800-273-8255. They'll help talk you through it.

These things have helped me in the past, along with talking on this site. You'll find other things that are more custom to you.
Stay strong.