What about being very humorless and particularly rigid?

I've already thought about the job issue now, and I'm going to do it for two more years. Because the current economic situation is really no way to put down this job, because all aspects of the cost is too big, so decided to again bitter and tired to put these two years to hold down, save some money. When my child goes to school, if I really can't go on for various reasons, I will quit again. I don't think it will have too much impact on the child in two years. I was ready to find you on Sunday to do telephone counseling, about interpersonal relationships, but I'm very busy these days no time, so I would like to ask you a question here, I am a person who usually daily life, work and coworkers relationship is okay, there will be a few to talk to a good colleague, and other coworkers will sometimes talk and chat to maintain the general relationship, although it does not belong to the type of smooth lively, but in the eyes of everyone I character is not good. In everyone's eyes, I feel that my character is okay, does not belong to the kind of introverted people, but I do not know how, I'm especially afraid of a few people to go out to the party kind of occasion, at most one or two and my character is similar to the people can, but if it is a line of colleagues to go out to dinner party, or relatives at home to party, I would be very afraid, because to the kind of party occasions need to make jokes to mobilize the atmosphere, I am usually at this time! I will feel very depressed, very uncomfortable, because I am a very bad joke not humor, only say some family life of the general ordinary words, for those who flattered to lift up the words of people, or jokes basically do not speak. So every time this time I'm very unable to let go and have stage fright, and even inferiority complex. In two days my sister-in-law's son's birthday, (is my husband's own sister) they called us a family to go to the restaurant for dinner, I really don't want to go, every time this kind of occasion I am very rigid sitting there to eat, don't talk much, will not tease his son to play, feel a bit of the atmosphere is not there, and my husband although his mouth more than I would have said, but he's not the kind of people who will mobilize the atmosphere of the very active, so every time this kind of occasion all! So every time we have this kind of occasion, we feel strange and the atmosphere is so depressing. So every time I come to this kind of party a few days before, I will be very nervous and afraid. But I'm too embarrassed not to go. Please give me some advice. What should I do in this situation?