I've been riding about 10 months and everything seems to be progressing well except my ability to ride hills. I struggle so much on hills that I dread them and I am just before the panic stage when I start the climb. On long or steep hills - I push myself until it feels like my lungs are going to burst and I stop. The crazy thing is - I can rest about 15-20 seconds and then finish the climb with much less effort. What is up with that?