Let's look at the available sources in the Ununtu repositories for those packages:
$ apt-cache madison libpcre3
libpcre3 | 2:8.39-11 | http://us.archive.ubuntu.com/ubuntu cosmic/main amd64 Packages
Ah, there's the problem. On 18.10, you are telling apt to install -9 instead of -11. You're tying to install an OLDER version that's not in the 18.10 repos. This means you have unwisely added a non-Ubuntu source that is intended for an older release of Ubuntu (like 18.04).
When a release of Ubuntu is built from Debian sources, all the versions are synchronized. All of the thousands of package depend upon a single version of each dependency. And then that one version goes into the repos. That's why Ubuntu is referred to as a snapshot distro. When you change versions, you might break all those dependencies. And that's why a release-upgrade involved replacing thousands of packages...all the dependencies must be updated to the new snapshot.
The problem you have is caused by trying to add packages with 18.04 dependencies to an 18.10 system. It won't work without expert ongoing maintenance. You can add 18.10 packages to an 18.10 system, or you can add 18.04 packages to an 18.04 system. But you cannot cross versions with the risk of breaking your system quite horribly, so the whole distro, repos, releases, and apt are set up to stop you from doing that.
Now let's take a look at libssl:
$ apt-cache madison libssl1.1
libssl1.1 | 1.1.1-1ubuntu2.1 | http://us.archive.ubuntu.com/ubuntu cosmic-updates/main amd64 Packages
libssl1.1 | 1.1.1-1ubuntu2.1 | http://security.ubuntu.com/ubuntu cosmic-security/main amd64 Packages
libssl1.1 | 1.1.1-1ubuntu2 | http://us.archive.ubuntu.com/ubuntu cosmic/main amd64 Packages
Same problem. Version 1.1.0g-2ubuntu4.1 is in 18.04, not 18.10. You are trying to add 18.04 packages to an 18.10 system. Stop doing that.