IVF Cycle 1 Issue

I'm 34 yo and have been ttc for 1.5 years  now on my first cycle of IVF after two failed IUI with our issue being male factor infertility. On my appointment 2 days ago, I had 18 follicles. Today, got horrible news...doc says that only 6 follicles have matured, the remaining smaller follicles have not gotten any bigger since my last US. He doesn't have a good explanation because all of my tests/labs were normal, he didn't not expect this to happen. He started me on a small dose of meds bc he assumed I wouldn't need much. It's to late to increase the meds now bc the small follicles won't catch up. He brought up stopping the current cycle and restarting in 6 weeks at a higher dose of meds. This is such a curveball...didn't not expect this to happen. Feel like I've been hit by a ton of bricks. Anyone else had this happen?