I Am A Hypochondriac And It Is Ruining Me

I am 17 years old and it feels like I have been a hypochondriac forever but it has only been a few months. I was overweight and my mum continued to tell me I would be diabetic if I didn't do something. My health was poor and I was always sluggish and under the weather. I lost 13 kg through extensive dieting and felt amazing and completely eliminated my asthma. After an emotional roller coaster my weight packed back on and since regaining my weight I have noticed my health fears and paranoia are getting out of control.
My health slipped so suddenly and now little things set me off really bad. The first case I remember was when I was staying at my Aunt's, one morning I woke up with a funny tingly feeling at the back of my head, I decided to ignore it but after I had noticed it I worried about it more and more. With that I became obsessed with it and quickly looked for any horrible reason it would be there. Of coarse thinking about it made the feeling worse and far more noticeable and after 9 days I went to the doctor thinking I had a tumour, it was simply a pinched nerve. After that I became obsessed with a mole on my arm that was itchy and started believing I had breast cancer. They started as little thoughts at the back of my mind and became obsessions too, I would rant about it and research it, driving everyone in my house insane, I would not stop thinking something was wrong and fabricating pain out of my fear till I had some new problem with my body to obsess over or until a doctor told me I was fine. It had to happen sooner or later but I came down with a seasonal flu, This meant hell for my mind and anyone around me at the time. It has been 4 days now and what started with flu symptoms and body aches has become full blown shooting pain throughout my whole body. At first I thought this didn't feel like a normal flu, it was minus a sore throat and runny nose etc, only consisting of body pain and fatigue and I was not familiar with this kind of flu. I felt dazed and it felt like I was loosing touch with reality and I became terrified. 4 days of focussing on this pain and I know it wont stop if I don't stop thinking about it, it only gets worse. It seems impossible though, I will sit back and say "It's okay, It's all in my head" But that thought is no where near as strong as "What if I'm wrong" I know I am fine but I just can't tell myself and I just don't have a strong enough mind. It is clear that I will not recover if I don't change my mind frame. I am suffering horrible pain right now, my aches are now shooting pain because I can't stop worrying that it is something worse. I just want to get better so I can recover from this pain and any future mental anguish. Is there any way to recover from flu aches? Panadol has done nothing for me, better yet, how can I get control over my mind?