Hi there cherokeehippie,
It sounds to me like you have some anxiety regarding social situations and being out of your safety zone of your home. I struggle with these issues a lot too. Before I was a Christian, I had little motivation to want to do anything different. I was happy staying at home and being alone, or being with friends and family, visiting at other peoples homes, or going places with people that I felt comfortable with. I had a hard time going to certain places that I associated with being too chaotic or too many people.
But when I was born again, God's love was in my heart and I started to want to be around other people to share myself in some way. Getting involved in a church was a big deal to me because I felt it would help me learn to love other people and would give me opportunities to serve. It has been challenging but rewarding because now, instead of just being alone most of the time, there are times when I am stretched beyond my comfort zone and I think that is good for me. I'm getting involved in serving at my church and I have gotten to know a few people too. For the record, I am totally different from everyone at my church. I don't look like anyone else, I have obvious physical problems that isolate me somewhat, and my personality is like day and night to most people's. But I find that it's not an issue at all if you can believe that. It's an issue if I imagine what other people might be thinking, but I know that is wrong to do. We can't play mind reader. Sometimes when a person slights us or behaves unfriendly, it has nothing to do with who we are. There might be reasons for their actions that are totally unrelated. Or maybe they just aren't very loving. But you will find that most people are very decent and some are very kind as Christians should be. Why miss out on the good things in church because of people? Church is a great place to worship God with others, and also to learn about the bible. I try to fear God more than man, and that thought really helps me.
I like to think that God would encourage you to get out there and meet some other Christians. After all, God loves you and wants to prosper you. He has a plan for your life and all the goodness of God is in it. Having Christians friends that can encourage you and that you can learn with is a good thing, and God can help you in this.
I guess it's too late for this weekend's gathering. One thing I bet is that you didn't have enough time to plan for it, so that you could feel confident of your ability to attend and be comfortable. I say, if you think you might like to go in the future, come up with a game plan for attendance. You could even contact some of the people who run it and ask them questions about it. Plan out what kinds of food you could bring for the whole weekend that you don't have to keep in a cooler like peanut butter and jelly sandwiches, snack crackers, nuts, jerky, fruit, etc. (as well as a few items you can keep in a cooler for better eating/drinking), your basic camping gear, etc. I bet if you felt prepared before the next gathering, you could go with more confidence. I am not a very spontaneous person, so I know how a lack of a plan and sudden need to make a decision can affect anxiety levels.
P.S. I also want to add another thought that has helped me a lot. I realized that I rarely feel *good* about anything, but if I were to let that stop me from doing things, then I would be imprisoned by my feelings. My life is pretty narrow as it is, since I stay at home with a disability. But I don't want to let my anxiety rule me anymore. SO I do things even if I feel anxious and it gets me outside of myself which is good. There are some great verses that help me such as:
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For you did not receive a spirit that makes you a slave again to fear, but you received the Spirit of sonship.[ 8:15 Or adoption] And by him we cry, "Abba, Father."
-- Romans 8:15 (NIV)
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When I came to you, brothers, I did not come with eloquence or superior wisdom as I proclaimed to you the testimony about God. For I resolved to know nothing while I was with you except Jesus Christ and him crucified. I came to you in weakness and fear, and with much trembling. My message and my preaching were not with wise and persuasive words, but with a demonstration of the Spirit's power, so that your faith might not rest on men's wisdom, but on God's power.
--1 Cor 2:1-5 (NIV)
Notice that even Paul went to places and to see people where he felt fear. The word he uses there is "phobos" like our word "phobia", for fear. I think we know that kind of fear that imagines the worst. But we don't go in our own strength. God holds us up and would have us go.
No need to fight against your good God of Peace, who loves you muchly. 
