[tor-relays] Tor Process Being Killed on VPS

Hello, I have a VPS with 512 MB RAM. I run nothing on it except nginx and a Tor relay. The relay is an entry guard and moves about 20 MB/s. It seems that the kernel is killing the Tor process with "out of memory" errors. Are there any tips for mitigating this? I don't have the money right now to upgrade to the next higher VPS plan which has more RAM, unfortunately. Maybe there's some config settings that I can modify to limit the RAM usage? Or, am I just out of luck? Thanks, Steve