My husband currently resides in India and I regularly embark on long flights to visit him, sometimes as long as 24 hours
(About to leave again in a week as a matter of fact)
Because I know I need to make these trips, I've learned to manage my anxiety to a comfortable level. I'll give my tried and true tips from a seasoned traveler with Panic Disorder and Hypochondria.
1.) Drink plenty of water before and during your flight/bus. I had no idea how dehydration made my anxiety so much worse. Planes tends to be very dry so definitely drink up once you clear security. I usually buy two big bottles before I board my flight or fill up my personal bottle.
2.) Bring lots of comforting, distracting things. Fill up your ipod/phone with good music that makes you think of pleasant memories. If you have a tablet, bring that along or a good book/magazine.
3.) Wear compression socks. This is mostly my health anxiety fears kicking in and it could be all in my head but I feel better when I wear my compression socks.
4.) Bring an essential "travel first aid kit". I made up my own just to be prepared for the unexpected. India is not NYC so you probably won't need everything in this list. Contents of my travel first aid kit: Pepto-Bismol tablets, hand sanitizer, eye drops, Neosporin, Benadryl, band aids, Imodium, advil, UV toothbrush case and extra batteries. This kit contains most of the essentials that will get you by with most common illnesses. I also carry a prescription of Cipro which I don't think you will need. (For traveler's diarrhea)
5.) Concentrate on imagining yourself enjoying your trip rather than dreading the thought of having a panic attack. I know it sounds cliché but in the past when I stressed about having a panic attack on my long flight, I ended up having that exact thing happen. The last few trips, I imagined my husband's face waiting for me at the airport, how much I missed him, and how good it would be to spend time together. Guess what? On my last trip, I had not a single panic attack, and did not get sick once, other than a very mild case of indigestion for a night or two.
6.) I personally do not take Xanax, Ativan or other drugs for my anxiety but I do have a prescription for Xanax. I carry it in my purse "just in case" and believe it or not, just the thought of knowing it is there in case of an emergency makes me feel comfort enough that I don't even need it.
7.) Have a good trip! This is the most important thing. You are going there to have fun and enjoy yourself. The worst thing that could happen is that you might have a panic attack in which case, you've managed it in the past before and you will get through it this time as well! I truly think you will be having so much fun, you will forget all about a potential panic attack. Also, if you do need to go to the hospital, you will be in NYC and a hospital is right around the corner.