I Am 43 And Have Always Been Fit. 5 Foot

I am 43 and have always been fit. 5 foot tall saize 6. For the past month I'd I walk up stairs and only up my heart pounds so heavily. Feel about dizzy and focus to regain normal breating. Very scary. I've stopped working out in fear of this issue so now I have gained 5 lbs, not helpful. Only change in life has been what appears sudden anxiety and major dental and jaw surgery two months ago. I will be seeing a Doctor once I get my new insurance card. Please help, I'm open to suggestions and yes I will still go see a Dr.