Why can't I sit myself down to study?

I’ve been in university for 3 years now (this is the 3rd) and each year I’ve been changing programs and universities. This year even countries. I lived in Cyprus but went to Canada for university. 1st year was in Quebec and was doing Math aiming to get a Bachelor’s degree in Math and then go into education, started of doing well but then 2nd semester just failed almost everything. Of course other things played a role as well not just the fact that I didn’t want to study. 2nd year went to Ontario and was doing Recreation and Leisure because they accepted me there instead of in Physical Education where I had applied in the first place. My favourite subjects in school were always Physical Education and Math (strange combination I know) and ever since I started dancing I love it and still do. So when I finished highschool I applied to different universities different programs and got a few different offers but chose math at a uni that was closest to where my sis was basically. Now I am back home in Cyprus, came back because I messed up in school and in life in Canada. My parents said I have to get a degree in something so since here in Cyprus with Business Administration you will definately get a job for sure that’s what I’m doing this year. Did ok last semester but I know I won’t this semester because I’m not studying like I should be. I’m not understanding some of the courses I’m taking either which are important courses in this program and I hate them. Basically I’d rather do chemistry which I hated in highschool when I did it rather than accounting that I’m doing now. But most importantly I’m not sitting down to study and focus on my courses. Why? What is wrong with me? I was never a brilliant student but did study hard and try my best and got good grades. But not anymore.