Two month old always on the nipple

It seems like my two month old baby girl is constantly on my nipple. I can never put her down even when she's sleeping because shells just wake back up and want to eat more. I know shess getting milk because I see it dribble out of her mouth. She's gaining weight like she should too. I just need to know what to do because I need a break and want her dad to take her but sadly he can't feed her. Has anyone experienced this?