Is Physics for me?

Hey, im a 19 year old living in Canada. iv been looking for career options for a while, it seems i cant be completely sold on anything, till i found out about Physics, astronomy and cosmology i listen and read about Michio Kaku, Carl Sagan, Neil Degrasse Tyson and Lawrence Krauss, the stuff they say really interest me i could see myself living a life to help find the answers to all this big questions and as well help people, no matter their race, religion etc i really want to help people. so to get to the point if i am going to change my major and seek a degree in astrophysics or something similar i was wondering if the calculus and mathematics is hard, i was never one who easily connected the concepts in math class but i believe i have th will, is that enough to help me finsh? thanks