Em, it's so hard. We were TTC for 3.5 years (no known reason) so I know where you're coming from. People just don't think when they make comments like your friend, and often they have had no experience or have known anyone dealing with infertility. Don't feel bad for what you said to her and for getting upset. What you are going through is hard and there are going to be bad days. it might be an idea to go and seek some counselling if you think it will help you. I saw a counsellor and then I started seeing a naturopath. For some reason I didn't gel with the counsellor and felt more comfortable chatting with my NP. It's important to find someone you are comfortable with.
Good luck with your specialist. I hope this is your year.