A VPS will not be cheaper - but you may get more for your money (more storage, unlimited accounts).

For something simple try https://mailinabox.email/

> would love to switch to some VPS/root or anything where I can SSH and install, compile my own services, but something where security is high and support is 24/7 available.

Those sound like expensive requirements to me. You want managed self hosted email? Some else providing support will be expensive.