Single woman here.. looking to adopt. Have questions

I am in my mid 30s and very frustrated being childless and I have always wanted to be a mother. I love being an aunt but that is not enough. I do not see my marital status changing, and though I have a good government job, I am struggling a little, though I am working a second job right now so I can earn some money towards adoption fees, etc. I also have completed a class on fostering and currently in the process of doing that but not sure how that is going to be on me. Taking in kids and then having to give them up may be too hard on me, being chidless and all. I do know I may be able to adopt but this is up in the air. I can probably conceive on my own too but being single, it is a pain and not sure how much Im willing to spend on IUI's, and so on. Also, there are so many toddlers that need adopting and why bring more kids into this world. My house payment is very low too, which helps alot. I doubt I will have the finances to do a domestic adoption and I dont know if I want to deal with the emotional toll of the birth mother and whether or not she'll change her mind. After doign some research, I did find an agency and I filled out a pre-approval application for a Bulgarian child and did get approved so far, but need to send a $300 fee, etc. I left a message for the worker handing my file as I have alot of questions. What have you heard about Bulgarian children. etc. What are the chances of me getting a child under 5 that is not special needs and is healthy? Please feel free to PM me. I also would like to know what agency you used, who to avoid, etc. I know some of this cant be discussed on these boards so please message me. Thank you!