You can try using flag -C in ssh for compression (read the man page warning). Maybe you connection is slow because your ISP is doing traffic shaping, you could also try to tunnel to another port (443).
-C Requests compression of all data (including stdin, stdout,
stderr, and data for forwarded X11 and TCP connections). The
compression algorithm is the same used by gzip(1), and the
“level” can be controlled by the CompressionLevel option for pro‐
tocol version 1. Compression is desirable on modem lines and
other slow connections, but will only slow down things on fast
networks. The default value can be set on a host-by-host basis
in the configuration files; see the Compression option.