Im so depressed idk what to do ?

I've been this way for months now and its really taking its toll on me I've lost almost 20-30 pounds in a month it sucks I hate my life I miss this girl more than anything she left me about a month ago and I haven't forgot about it ugh I loved this girl she meant everything to me I can't go an hour without thinking of her idk what to do anymore its been eating me up inside I can't take this anymore ........