Why wont this bug go? Have you got any tips for boosting your immune system?

Hi everyone, in February I got a really nasty throat infection and I think possibly flu. The dr gave me high strength antibiotics and told me to rest but I had to go back to school because I was doing my PGCE and you're only allowed a few days off or you start having to come back for another term and I needed to get a job in september (she told me to have 2 weeks off). Anyway, I got it again a few weeks later and same thing - kids are riddling with germs. Ever since I've got every little thing going. Even when I didn't seem to have anything I was getting very high temperatures. About a month ago my partner brought home a really nasty flu from his london commuting and now we constantly are both getting high temperatures now and are consequently feeling gastly. We are going through paracetamol like there's no tomorrow. We are veggie and eat loads of fresh fruit and vegetable, haven't been drinking alcohol, drink lots of water and we are trying our best to rest (I'm in the school hols so I'm resting lots) but it just won't go. I could go to the drs but I'm sure they'll just say rest. Please help!!!! How can we shake this blasted thing off and boost our immunity?