I reviewed my logs again. Actually, the SSL connections were not of the format IP:50002. So, that hasn't changed since my server's last working state. I upgraded Ubuntu to 18.04 LTS and upgraded to python 3.7 which increased the number of connections to approximately 30, but I could still not connect via an Electrum client. Also, a couple months ago when I could connect I had about 10X the connections.
Furo4kin, have you looked at these issues?
https://github.com/kyuupichan/electrumx/issues/556https://github.com/kyuupichan/electrumx/issues/94Let me know if your logs match any output from these issues. Issue #556 seems to match the timeline of our problems. I am unsure where the weakest point would be in a DOS attack, but I suppose it would be my router.
Furo4kin, if you would like any more info as I learn more, I could PM you if you allow messages from newbies