Go to the party. There might be some tears, but if you miss it and still ship off to the four corners of the earth without it, you’ll undoubtedly regret it. The chances are that you’ll have a great time and not start crying until the party is over, or at the end. That’s OK. Your friends will be touched to know how it hurts you to think of parting from them. They might be very hurt that you were so afraid of crying that you wouldn’t give them a chance to mark this parting with you in a suitable way.
If you’re not leaving because you were fired from your job, heading off to prison, or for some other ignoble reason, this is a command performance. You need to go, so don’t even ask yourself if you want to go or not. Go with bells on, then.
Bring a little notebook and make sure you have a calendar handy, so you can write down plans for keeping in touch. What you talk about but do not write down will not happen.