Sorry to hear about your miscarriage. I think a lot of young woman have the urge to have children when they are young and that is because of our changes in hormones as we develop...but why rush into having to take care of another person. You are so young, and have the whole world in the palm of your hand. Having a baby cannot fill the void that you are feeling in your life, you have to be happy with yourself. I recommend going and talking to someone and finding out what it is deep down inside that is making you unhappy, before jumping into parenthood. There are a lot of rewards in being a mother, but it is a lot more work than you think, or even could imagine.
When I was 16 I thought that a baby would make me happy, fortunately I didnt have kids until I met my husband, and I was able to accomplish many things in life, that if I was to have a baby at a young age I wouldnt have met, or struggling to meet.
Accomplish your goals now before you are fully responsible for another person. Talk to someone professional about your depression and why you feel so low about yourself. Find that inner happiness.
Wish you the best of luck.