Tunneling through ssh

Hello All!

I am part of a LAN and I connect to the Internet through a gateway.
Currently my traffic e.g. smtp, ftp, pop3, etc. goes through the
gateway in cleartext. However, I would like to tunnel ALL my traffic
through ssh through that gateway. I do not have another system
connected to the Internet on the other end i.e. outside of my LAN.

Are there any public systems or services which can accept the tunneled
traffic and then route it to appropriate destination.

Or is there any other alternative to achieve this?

Thanks in advance!