Orgasm talk

I'm 18 years old had have been sextually active for abiut a year. And through out all this time I haven't been able to reach completion...as of right now I feel like something is wrong with me since sex feels good but not shooting fireworks good like everybody says it is. When my boyfriend goes down there isn't much action and sometimes it doesn't feel so great. Am I crazy? Should I be worried? Is there a way that I can climax???