Can seomone help me on my univesity decision please? :/?

Hey, I know it's ultimately my decision but I am 17 years old and I am in college and basically I need advice because I am in two minds about university. At the moment I am about to sit my last few exams at A level and I already have an A in History and I only need 50-60% in my Geogrpahy and Law exams to achieve and A because I have done so well in my other exams. I want to become a primary school teacher/secondary school teacher...I have no preference because I would just like to teach. I have applied to universities and Exeter, Leeds and Bristol have given me realistic offers...however I have changed my mind about going to university this year because I suffer from chronic headaches and it is very stressful and I find it difficult to concentrate. I am also in a relationship of only 2 months but she has been my best friend for a year and a half and we have something special (she says she does'nt want to get in my way, but I love her :/ ). I am sick of college at the moment and I doubt I can stick out 4 years in England when I am from South Wales, but my family is pushing for me to go to university. Can I have advice on what I should do after finishing my A level exams, I want to go to university after taking a gap year, but what can I do during the gap year? Thanks in advance