As it happens, I have the exact same SSD and had the exact same problem. Luckily, there's a crazy easy solution. Just use Steam Mover
. It lets you painlessly move your Steam games between drives and creates symbolic links so the games which aren't on your SSD still work through Steam as if they were. I use it to keep my two most played games on my SSD, and the rest stay in storage until I want to play them.
If you've got a good storage drive (7200 RPM, not badly fragmented) most games can be moved in just a minute or two. It's an absolute must have for anyone with Steam and an SSD.