I am always the best in chem lab (my labs are always performed correctly with very little error I get great grades on the labs I think it's really easy) and I love chem and want it to be my major but I work my off to barley pass chem lecture... should I change my major?

The same thing happen to me , am good in electrical lab but barely pass my electrical engg lecture, but with my practical/lab I almost excel with my work and even my prof assign me as his asst. and somebody adz me to shift to technical course and from there I enjoy the course because all we do there are all practical and I enjoy everything , so maybe you can try first shifting to chem lab tech.

If you like chemistry and know ways in which you can use your degree then I wouldn't change your major just yet unless you truly want to try something different. Lecture is the hardest part and you have to get inspired and practice a little self discipline when it comes to that. You are obviously good at the subject. Keep in mind though, every major is going to involve boring lectures that are hard to focus on and study for.