To early to feel like this??

Been extremely exhausted lately. I can barely carry my 1yo son and I walk at a snail speed to keep from having to stop to catch ny breath and let my heart stop racing. When climbing stairs I can only make it up a few before stopping to rest. I didn't feel like this during my last pregnancy. I was able to do normal daily activities with ease and was even chasing our pigs with no trouble at all. I am only 19 weeks along. I could understand if I was close to delivery but I've got a long way to go to be feeling like this already. Any personal experiences or suggestions to help me get through this?