Breathless, I really need help.

Eva • I am from Virginia, my husband and I love our son who was born on 10/05/15 and now are pregnant with baby #2!❤️
I am a ftm, and I am 12 weeks tomorrow. I am becoming very breathless. I can't walk or stand for more than 15 mins without feeling like I cannot breathe and then I get dizzy and lightheaded. And most times I will throw up. If anyone has any info on this or when it stops please help!!