As someone who works in the banking industry here is the advice I am going to give you.
1) Contact Citibank IMMEDIATELY! Find out if there is any amount you can pay now towards the debt in good faith that you will continue to pay the rest. Work out a payment plan. Citibank does not want to have to come and collect your items - they are to big to be interested in that. But they will do it if you give them no other choice.
2) Great job on paying off your truck and other various loans. However you do realize that this one Citibank card is going to ruin your credit? You now need to concentrate all of your available funds towards the Citicard. As a business owner it is not a good idea to have bad credit.
3) Once you work out a payment plan- pay more to it. Citibank is not going to go away.
4) You could go to a credit advisor if you can't work out a payment plan to Citibank. Or you could also file bankruptcy. I don't really reccommend either since they are black marks on your credit. Again it doens't look good for a business owner to file bankruptcy.
5) We all rack up debt in the college years. I know I've done it as well so I completely understand where you are coming from. The best thing to do is own up to your mistakes and pay it off.
Go on your trip - but if you don't think you can keep it to a $1000 then cancel it. No sense in going into even more debt. Also tell yourself now that any tax return you receive is going to go towards that $11,000. Make no other plans for the money.
There seems to be an awful lot of judgemental people on this thread. I don't think you meant to get this kind of backlash, but some people take it personal when others didn't do as well in life as they did.

I say ignore those people and concentrate on what you can do.
~Amanda