too many command blocks crash

so i have this server project, a pvp game, fully run by command blocks and redstone, and its been laggy for a while, even through my pc should be able to handle it.

now comes the strange part. i can understand command blocks might make it a little laggy... but they are actually also capable of crashing a server. i have added a few more yesterday, and now the server crashes randomly. i have attached the crash log.