Something is really weighing on my heart

I have a desire to be a mother so bad, the method doesn't matter. I work at a daycare and I want to take all the kids home. I've never wanted to be anything more than a mother in life. I am 21 years old and want to adopt but husband isn't up for adopting or having kids. He already has 2, is fixed, and stays pretty busy with them. I just can't get over this, and it hurts so bad. I cry and pray God will some how send me a child. Adoption seems to be on my mind a lot, and I feel like it's a sign. Any advice?