First, thanks for actually replying/answering questions - so many people say they want help but don't give information to allow help to be given!!
Second, you need to start to take action to help yourself!!

so, please start taking a walk 30-60 minutes at around dawn (weather permitting - overcast is ok, but don't get ill in rain etc!! - that won't help!!) try & get a good basic yoga video/dvd that includes yoga meditation (kill 2 birds with one stone) & start doing these too. At your age & as you already do sport your only real problem with this might be the relaxing but my daughter (16) found that doing the meditation in with the yoga was better than trying to actually do a relaxation tape etc.
Both of the above are free/cheap (you could even borrow a yoga tape (library) or 2 & test them out to see what suits you). So there's no excuse except fear/stress & that is what you need to overcome.
Third, where exactly do the blood spots appear?? Face?? Sweat areas?? All over??
fourth, have you changed your diet, job, home environment or travelled recently (like before this started!!)???? I had been overseas for awhile, came home & about 2-3 months later broke out in this horrid rash all around my mouth - the dr explained that sometimes life changes can cause al sorts of odd reactions & this is all it was, once I settled down etc & calmed down about the rash!!!!!!!!

it went away. Stress & change can do weird things.