Help with Adopting

Hello, my husband and I have been TTC for 6 years now and have done all we can, fertility treatments, trying, not trying, medications, etc. we are tired. We want to adopt but have no clue where to start. We are not rich or but we are a middle class couple. We do own our own home. Does anyone have any recommendations on where to start with the adoption process? Any agencies they would recommend that are not super expensive. We were looking for younger infant-5years.

Also, we looked into fostering but we think it would be to hard to fall in love with a child and have to give them up.

Any opinions and stories help, thank you!