1000 emails to 10 meetings is really low conversion. It could be an issue of PMF, or who you are reaching out to, or the messaging of the emails, or a combination. I would try to find an experienced seller to partner with who can bankroll themselves in exchange for some generous equity. At this point you need their experience to build things back up. On messaging, I would suggest something along the lines of:

Prospect,

I noticed that (indication that they have the problem you solve). Have you considered (thing you do differently than their existing solution).

(my company) has built a new way to (solve the problem you hypothesize they have). Solving this problem would (allude to the promise land = more money or less costs or easier work or all three). Without our solution (scary things happen). I'd like to connect for 15 minutes and explore how you approach (the problem you solve) now to see if there is a fit.

Are you free (day and time)?

Pain, value, call to action. There are no hard and fast rules, but you should be getting significantly more than 100:1 outreach to meetings. Only ask for 15 minutes. The first call your goal is only to qualify. No tire kickers allowed. Is there budget? Do you actually have this problem? Who else needs to be involved to decide?

Ask 3-5 questions getting to the bottom of 1. How it's done there now and 2. Your synthesis of whether you think there is value. If you don't think there is value, straight up tell them. "It doesn't seem the like the value is there at this point, I appreciate you taking the time". If there is value, push hard. What needs to happen next to understand if this is a fit? Who needs to be involved? DO NOT offer a demo or a free trial. It does not win deals and puts you in a position of weakness.

You should be able to send 100 cold emails in a day if you grind. That should convert into 4-5 15 minute meetings with customers. That should result in 1-2 qualified deals. Most top sellers convert about 33-35% of qualified deals into money. Your sales cycles may be long, in which case I am sorry but it is what it is. If you can generate those 5-10 deals per week, you should be able to convert 2-3 of them. Any worse and the issue is product/market fit and probably not the sales process (probably).

It sounds like you sell to big companies (Directors?). If so, call high. Do not call people who do not sign cheques. Even if they delegate you down (which they often will) it is usually easier to get a response from senior people. Junior people prioritize what their boss tells them where as senior people tend to be more open. If you nail the hypothesis in the email (we call it "the hook") then you will get a response. If you don't, you won't, but at least you can disprove a particular hook.

In terms of cadence, try two emails and one follow-up call a week for three weeks. It seems obscene but it is necessary. You would be amazed how many people reply on the 5th email saying they have been looking for the exact solution you are describing. Of course, only 1/3 of those people actually end up giving you money (because people) but at least your persistence will make an imprint. You would also be amazed, after doing this work for a year or two, how many people come back to the table in six months.

Better engineering and product != success. Seriously, distribution wins almost every time. Stop worrying about product, whether it is amazing or just decent does not matter anymore. The only thing that matters is securing distribution. You have a distribution problem, 100%. If you try the sales route and fail, the best case scenario would be to sell the company to someone who does have distribution. Then they can plug your theoretically superior technology into their distribution.