OP whatever you do in life, whoever you are, some people will judge and disapprove. We are all different and all have differing views on what we consider to be OK, particularly when it comes to children.
You can't let the views of a small minority dictate how you live your life.
Can I make a suggestion? Find an infertility chat forum (some clinics have them) and you will come across many people in your situation. It will help normalise it for you, and stop you feeling dirty.
I live in a small village where no one is even divorced, never mind having donor sperm kids. Everyone is very nice to me, but I'm sure that some people disapprove behind my back. But I have trained myself not to care. I know I am a good mum. Yes my kids don't have a dad, and yes there may be serious fall-out from that in future, but they are loved, they were wanted, I made HUGE sacrifices to have them, they will never lie in bed feeling terrified hearing their parents yelling at eachother, I devote my life to them and making them happy. Whatever happens in the future, I have nothing to feel ashamed of, and anyone who says I do is narrow-minded, bigoted, ignorant and nasty, in my opinion!