Brown spots on skin, could it be skin cancer?

hi i am 16 and i am worried because i have about 15 small brown patches on my lower shoulders/upper back. i only had 1 a year ago and the doctor said it was a wart and sprayed it with ice stuff. it came back about a month later and now here i am with a dozen more. the first one is bigger (about 1.25 cm in diameter, and the others are pretty small). i also noticed i now have a red sore in the middle of my back. i have a ton of huge freckles on my back, and this summer i got a pretty good sunburn (blisters, extreme itching etc.) Oh, i also have 2 very small but very dark black dots on my lower neck. any ideas?

10 hours ago - 4 days left to answer.

Additional Details

- the patches are light brown and stick out slightly

- the biggest patch has jagged edges

- the other patches are ovals

- i did not notice the smaller patches until about a month ago

- the patches itch every now and than when rubbing against fabric

- they dont hurt

- i dont have a dermotologist within 40 miles and i couldn't get an appointment until 1/24, so i decided to hold off for a few days.

- what is the probability of me having skin cancer?