I had balloon sinusplasty and was prescribed methylprednisolone and levofloxacin . i am 33 and i read these medication have an interaction my doctor said it was okay to take, but i am still worried of developing tendonitis. i'm really worried?

Your concern is valid. However, the quoted incidence rate for tendinopathy is 0.1% to 0.01%, and the quoted incidence rate for tendon rupture is less than 0.01%. Therefore, if the antibiotic is indicated due to active infection, the downside risk is low and the potential benefit is high. However, in the absence of infection, prophylactic antibiotic use has been questioned.