My left testicle hurts for one week now after over musterbation. My left testicle feels warm (the weather is getting cold) but I don't have pain with erecttion or urination. I don't have blood in urine. Is it dangrues or I need rest?

Watch and wait. If the pain and warmth are subsiding, you may wait it out and let it rest and heal. If it is not better in a week or gets worse, see a doctor.
For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Drink enough water daily, so that your urine is mostly colorless. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form.
Practice safe sex, if you have sex.