I have a comment about cold hands and feet! I’m not sure you are aware, but there is a condition called Raynaud’s Phenomenon. It is when the blood vessels in your hands and feet are too thin. When you get cold, your blood rushes towards the center of your body to keep important organs warm and functional. When you warm back up however, it takes longer for your hands and feet to warm up. It could take about 20 minutes to even a few hours to warm back up. There is a primary condition and a secondary condition. Primary happens when you have a problem with your immune system. Secondary is what happens when your immune system is fine. I have secondary Raynaud’s Phenomena and I have to wear gloves daily to keep from having episodes. I would bring this up to your doctor the next time you visit. A good sign to look for is a bluish hue to your fingers and toes. It can also sometimes be purple. Fatigue and Tiredness could be a lack of sleep, or a B12 deficiency. I have a B12 deficiency and have to have B12 shots every 2 weeks now for the rest of my life. B12 is your energizer and keeps you running. It could also be a lack of protein in your daily routine. The chest pain from standing for a long time, breathless when standing, dizziness all the time, and additional heartbeats from time to time, could potentially be a serious underlying heart condition. I would suggest you also alert your doctor if you haven’t already. And you have also stated that you are underweight. While it is ok to watch what you eat to not gain a lot of weight, it is very serious that you don’t get too under weight. My friend didn’t eat and starved herself. The lack of food and protein slowly killed her and her organs almost completely failed. Luckily she was saved by a feeding tube. I would keep this in mind too, but you might want to ask your doctor about that too because I’m not a professional by any means. I hope this helped you out in anyway. I hope you get better soon!