Suggest Treatment For Sinus Pressure And Congestion

I m a 55 yo female post-menapausal in good health with hypothyroidism well controlled on Levoxyl. I try to watch what I eat and exercise. No family history of heart or neurological, etc. issues. In last six months began having sinus issues, congestion, sinus pressure, and lightheadedness (feels like I m on a moving boat). My apartment had mold issues and I moved in April. I ve been prescribed antibiotics 3 times in last six months for sinusitis which helped these symptoms for a short time, but the lightheadedness continues to be for part of the day every day. I ve taken Meclizine with no change. Sometimes I have runny nose, headache or sinus pressure with it but not always. I don t know what to consider next if none of the sinus remedies are helpful.