Cant get on my own MC server HELP

I start up my minecraft server, and it works, then i time out due to lag. I cant get back on the server at all. The task manager says its running though, but though it usually runs at 300,000KB, its running at 21,000KB. I've tried turning my laptop off and on and restarting the server. It still doesnt work. HELP!!!!!!!!!!!!!!!!!!!!!!!!!