ssh connection refused on Debian 7

I cannot ssh to my Debian 7 server anymore. It happened after I tried to upgrade some packages on this old distro (including libc6…). Uptime is almost 2200 days! I do not even want to risk restarting it.

ssh -V returns OpenSSH_6.0p1 Debian-4+deb7u7, OpenSSL 1.0.1t 3 May 2016

I somehow still have an active ssh connection on Putty as a root so I can still run commands. Hopefully I will not lose it before I fix this massive issue!

nothing outputs when I run /etc/init.d/ssh restart, it just prompts a new line for new commands.

ps -f -p $(pgrep sshd) shows a pid and uid root

/usr/sbin/sshd does not exist

cat /etc/ssh/sshd_config shows nothing any different than it has always been. I run it on port 22000. No issues since 6 years until now. I now explicitly opened the port 22000 on iptables just to make sure but nothing changed.

sftp -oPort=22000 -vvv root@redacted_for_privacy shows

OpenSSH_6.0p1 Debian-4+deb7u7, OpenSSL 1.0.1t  3 May 2016
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug2: ssh_connect: needpriv 0
debug1: Connecting to redacted_for_privacy (123.456.redacted_for_privacy.123) port 22000.
debug1: connect to address 123.456.redacted_for_privacy.123 port 22000: Connection refused
ssh: connect to host redacted_for_privacy port 22000: Connection refused
Couldn't read packet: Connection reset by peer

command netstat -tulpn | grep 22000 returns nothing, however it does return udp6 for 22

command ps aux | grep sshd returns :

root     12247  0.0  0.0  29920  1252 pts/0    T    Nov21   0:00 vim /etc/ssh/sshd_config
root     12248  0.0  0.0  29924  1308 pts/0    T    Nov21   0:00 vim /etc/ssh/sshd_config
root     25974  0.0  0.0   6312   788 pts/0    S+   01:09   0:00 grep sshd
root     31003  0.0  0.0  81232  3932 ?        Ss   Nov21   0:14 sshd: root@pts/0

vim is because i set PermitRootLogin yes (it had always been set at without-password). 31003 is sshd pid

I also tried to reinstall:
apt-get install openssh-server but it returned
openssh-server : Depends: openssh-client (= 1:6.0p1-4+deb7u4) but 1:6.0p1-4+deb7u7 is to be installed
and E: Unable to correct problems, you have held broken packages. which is probably very true considering the ugly tinkerings I tried in order to upgrade libc6!

tail -f /var/log/auth.log when I try to ssh via WinSCP does not show any new line appending. either trying on port 22 or custom 22000.

netstat -ntlp returns

Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 0.0.0.0:21              0.0.0.0:*               LISTEN      12431/proftpd: (acc
tcp        0      0 0.0.0.0:3129            0.0.0.0:*               LISTEN      4374/(squid)
tcp        0      0 0.0.0.0:443             0.0.0.0:*               LISTEN      4917/nginx
tcp        0      0 127.0.0.1:3306          0.0.0.0:*               LISTEN      7231/mysqld
tcp        0      0 0.0.0.0:10000           0.0.0.0:*               LISTEN      10330/perl
tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      4917/nginx

I tried behind a different ip, I’m sure I did not jail myself.

The 4 websites hosted on it currently keep working as if nothing ever happened.

I am out of ideas and desperate. What else should I check/try? I believe it is not running sshd but I have not idea how to restart it. I do not have systemctl, neihter service sshd restart, and nothing in /etc/init.d/