Technical SEO Problem

We need a technical SEO expert who can solve a problem that shut our business down in June. I have a Wordpress site. We provide consulting services and training materials to major businesses worldwide, but mostly in the USA. In early June, we were getting 30-50 leads each week via submitted WP forms. Then had 18 lead forms in the middle of June and one at the end of June. Every week from the week of June 16, we have received 0-3 leads each week. Something turned the light switch off. It is probably a technical SEO problem. I want to know what did it and want to fix it immediately within 30 days. Beyond fixing this problem, I will be willing to agree to a longer term plan to make additional improvements.