Lag help!

Hello, i downloaded this awesome mod today and played it and everything
worked fine, i got to the part when you get your crowbar and then i saved game and turned off my laptop (hibernated). Now when i started the game
i get TERRIBLE lag even on minimal settings. My FPS is ~5.
What happened?? I have HP ProBook 4535s

Founded in 2004, Leakfree.org became one of the first online communities dedicated to Valve’s Source engine development. It is more famously known for the formation of Black Mesa: Source under the 'Leakfree Modification Team' handle in September 2004.