It's not clear to me how much control you have over your server. If you can log into it, get to a Bash shell, and run commands as root, then you should be able to set it up to have a free SSL certificate from Let's Encrypt. That is what I would recommend. You should not pay for SSL certificates because free ones from Let's Encrypt that automatically renew have been available for many years.
https://letsencrypt.org/Like you, I don't believe browsers will outright block non-secure websites any time soon. But I have heard that search engines give non-secure sites less priority when ranking their results.
--David