I'm sorry it didn't go the way you'd hoped, I was speaking to a friend the other day and we were saying how frustrating it is when you go to the Dr and walk away no clearer about what's wrong.
So your positives are;
There's nothing new or sinister shown up.
Your ovaries look healthy so no reason you can't produce eggs.
You are already familiar with the clinic you are being referred to.
Your clinic will already have notes about tests/procedures and results from before as well as how you responded so may not need to do everything again.
You still may conceive naturally but at least you're starting the other process.
I'm sorry it's not been simpler the 2nd time around, I know that sometimes women manage a spontaneous pregnancy after an ivf one and that may well happen. My friend was told that, due to PSOS and thyroid problems for her and low count and poor motility for DH there was no chance of conceiving without ICSI, they were both shocked and confused when she found herself expecting (to the point where her husband asked if she'd been with anyone else!).
Number 2 can still happen for you, listen to what the clinic suggest and then see how you feel. I'll keep everything crossed for you and will look forward to hearing how it all goes. Xx