I am a server and very rarely do I get into some bouts of breath shortness but I do. It's happened twice in a month now and I am a little concerned. The other thing is I have to sit down for quite some time before it goes away. It always feels like my heart jumped into my throat and I don't understand it. I tried to drink some water or some seltzer water with lemon but it didn't help and eventually it just goes away after a little while. The other problem is since I'm on my feet all day I get these pains in my calves and thighs. It feels like I had been running a mile but I've actually only been walking fast, like I usually do at my job. At first it was my feet and I fixed that by getting some new shoes with gel insoles and now my legs. Can someone help please? Am I missing some kind of vitamin, mineral, or something else? Or am I just not in shape for this kind of work even though I've been doing it five days a week for the past 6 months and before that about four days a week for about a year and half. Please help!

My b/f thinks I might be out of shape, I have no doubt about that but is it something else?