sinus, very tired all the time, cough, dark uner eye, grumpy

One of my children has had signs of a cold, flu symptoms for about 5 weeks . Very tired all the time. A second son very tired. I wake up with headaches eye pressure tired. We just moved into a rental.home about 1 mile from beach . My older son has also become very grumpy. Wondering maybe mold? House had new paint carpet bathroom flooring before we moved in . Any ideas ?