I only have one dynamic IP address. The other listed IPs are internal
Right, that makes all the difference! You didn't say that in the original post, nor in two of your follow-ups and it's details like that which make a difference.
Are there any other seemingly-minor details we need to know about? Since the sslh daemon will introduce an up-to-two-seconds delay, can you tolerate that?
What restrictions are being put on you that forces you to use 443 for both services? Are you trying to bypass a workplace policy of some kind?
Are the HTTPS and SSH servers for your own use or for general public use?
Can you use 465 (SMTPS) or 993 (IMAPS) for SSH, for example?
If it's largely for your own use, use SSH tunnels, stunnel or OpenVPN and multiplex the connections over a single secure channel.
Details!