Symptoms from open chest surgery? - 1271825

Hi had median sternomany for stage 2 thymoma cancer encapsulated looks clear margin I have had breathing problems feels like a lot mucus dripping and I feel like I'm drowning kinda some swelling upper chest and top of breast I ask doc but say my lungs are clear and breathing sounds good very labored breathing after little activity can this be still from surgery it was at the end of May 2015