Google Ads optimization expert needed

We are a Seattle-based performance ad network established in 2013 that has until very recently been focused on CPA/CPL/CPS/CPI campaign models where most traffic is driven by our affiliates or by our own internal media buys on display, interstitial, pop, push, etc. platforms. Recently, we launched a new pay-per-call side of our network and our initial call-generating efforts have been via paid search in Google and Bing, and some social in FB and soon to test in TikTok, Snapchat and YouTube. With our Google call only ads (we are only paid on valid, connected calls of various durations depending on the buyer/vertical), we are generating a lot of inbound calls, but our team members are not experts at optimization, so we are consistently losing money on our Google call only ads despite generating calls. So, we are looking for a true Google Ads optimization expert who can also help us ensure we are selecting the best keywords and negative keywords in our campaigns, set the correct bid strategies, use any targeting methods we aren't aware of/aren't using, and then analyze the data collected to help us optimize the campaigns to remove underperforming kw's, set manual cpc's where suggested, etc. in order to return at least a 50% positive ROI on our campaigns. Our current main vertical that we are focused on scaling is Flight Booking calls. We need to reach a maximum spend of $7 per inbound call in order to be profitable (anything under that would be even better - getting to under $5 would be amazing and would allow us to open budgets significantly). During the last month, we had gone from about a $22 per call cost down to about $8, but then the ads stopped generating any traffic at all hardly. So I suspect we have made mistakes in optimizing. So, in essence, we need help! We need someone to get our campaign into a positive ROI performance range asap. If we can find the right person, we would happily work with him/her for the long-term on all of the additional verticals we are rolling out in the per-call side of our network including health insurance, pest services, auto insurance, addiction rehab, final expense insurance and many others. Does this sound like something you would be able to work with us on, and if so, what would you charge and what would be the timeline on getting our campaigns reviewed and initial optimizations done? Thanks!