Take Sudafed or its generic "Pseudoepherine hydrocloride" as you want to. it sounds like your sinuses are blocked. Increase the moisture in your environment. Use a Nettie pot of you have acess to one, if not you can do the same thing standing in the shower, blow your nose a few times at the end of a long shower, if still not open, cup your hand and get sone water in it, hold it to one nostril andsuck it up your nose. hold for a few seconds and then blow. some times this needs to be repeated. Antihistamines will slow down the removal of toxins so if possible you might want to aviod them until last. But using them should not cause any harm, just slow down the removal of the toxins you body is trying to get rid of.