18 million to Zero

Six months ago we were so excited that my SO's had increased to 18 million from 8.5 million. We decided to try <a href="https://glowing.com/glow-fertility-program">IUI</a> this month and I took Femara and a trigger shot. We got there this morning to do the insemination and my SO had absolutely NO SPERM. We were devastated. Has anyone else had their SO's count drop so drastically and quickly? Really need some positive situations because we are losing hope on having a baby of our own.