Health Anxiety is taking over my life!

Hi, I am a 19 year old Female. So long story short i started with some leg pains (felt like growing pains at start) and they got a bit annoying so i took some ibuprofen which worked a little bit. Then i noticed a bit of swelling on my calf which looked to be on the muscle but i panicked so called the doctor and they suspected DVT (Deep Vein Thrombosis) so sent me to A&E. Luckily i did not have DVT but the doctor i spoke to brought anxiety into the conversation which really bugged me because he basically tried saying the pains were in my head even tho i had a physical lump of evidence to show. Called the doctors again and they booked me an ultrasound and that come back clear but i am still sure they are missing something. I started to google things and log my symptoms and every new symptom i got, i googled it and it obviously come up with terminal illnesses and conditions which i am petrified of. The lump does not hurt and it isn't very noticeable now which is what i think, a good sign. But the pains have not stopped. They are mostly in one leg (my left) but radiate from all my limbs. I suspected muscle pain at the start but it now feels like bones and joints. Spoke to another doctor who prescribed me some Vitamin B12 tablets when my blood levels were al fine apparently!! And i refuse to start these tablets as i do not think that is the cause of my pain. I have another telephone doctors appointment at some time today and i am going to demand to get seen to. But moral of the story is no matter what the doctors and health professionals are saying, i do not believe them and it is getting very unhealthy, ruining my social and work life and making me unwell as it is all i think about every single day. I know i have physical symptoms to show for my concerns but i have other aches and pains that i google and all i can think is the dreaded c word... Cancer. In the past 3 months i have diagnosed myself with Leukemia , Osteosarcoma , Appendicitis, Stomach ulcers, Bowel cancer, ovarian cysts and Cancer, Arthiritis, A heart attack... and believe it or not, the list goes on. Unfortunately, some people around me call me a hypochondriac and tell me i am being dramatic but this is something i live with every single day and it never gets better for me. I am worried that even when i get some scans and more tests done, the feeling wont go away. I do not want to be diagnosed anything but i feel like if i get told i am okay, ill only keep worrying. So sorry for the long paragraphs, i need to speak to people who relate. Thank you for your time.