IVF Beginner

So we just found out that my husband has zero sperm count at least when it comes to the ejaculation, the doctor said the part of his testis that should shoot out the sperm doesn't work cause of past trauma and that we will have to do IVF for sure...... we haven't spoken about the process yet, cause I'm still losing weight myself and getting tested on my end. I was curious on what the process is? Cost? Success stories? my husband and I have a huge age gape, I'm 20 and he is 42. She plans on starting him on some medicine after she gets some gentic testing done, and then starting me on metformin. I'm really scared I won't ever be able to have children.