Selfhosted

You should be concerned, because there is always a risk, but there is also a risk when you are just using internet even without selfhosting. It is good to remember some rules:

1. Keep apps up to date
2. Open only that ports, that you need (80, 443, maybe 22 for ssh)
3. If you open ssh port, use keys authentication and cut possibility logging with password
4. Do not expose apps, that you are not need in this form, for example Yunohost allows to hide apps behind Yunohost SSO logging page
5. Using cloudflare or/and Fail2Ban is cool
6. Maybe I am a little bit paranoic, but I do not expose apps, that can be used anonymously by everyone, for example link shorters or pastebin alternatives.

It is not all of course.

Isolate your programs, keep the critical stuff away from the public using tailscale or a VPN, hell, even an SSH tunnel could work in your case, make sure to keep different password for each software for your database. If possible virtualize each software to keep them from communicating to other softwares. This is how i manage my infrastructure (or should be, i haven't gotten yet to use tailscale for admin only websites).

Password protect your services, set up your web server correctly, use cloudflare for some extra security against stuff like DDoS/DoS attacks. Also less is more, do not expose what you don't need to expose.

There is always inherent risk with opening up your stuff to the world wide web.

Some stuff you can't even secure yourself; some services just have bad security practices. The only way to fix them would be to wait for an update or submit a pull request.