Soft lump on side of neck

Hi there, i am 23 years old, since i was 13 i had a soft lump on the side of my neck probably 5 cms below the ear, the lump is highly mobile, it hasnt grown almost at all, also 5 years ago i discovered a very hard lump on my back probably around 1.5cms to 2 cms it doesnt hurt at all and i can grab it and pull it outwards and the five years i have discovered it it hasnt grown or felt any pain, i havent told any doctor for the first lump ten years and for the second lump 5 years is it possible to have a malignant tumor for 5 years and be fine? sometimes there are periods literaly months that im very scared and thinking of the lumps all the time and some other periods i forget they exist please help me!