I've been getting sinus headaches for over a week now. decongestants work for a few hours but nothing really works what shall i do now???

Sinus pain: Try afrin (oxymetazoline) (otrivin)nasal spray twice a day for not more than 5 days,if this does not help,you may need to have course of antibiotics.

Sinus infection: it sound like you might need some abx for a sinus infection. if you can't or won't take abx, you can do sinus rinses 2-3 times per day. those will get rid of a sinus infection as well, it will just take more time.