Mom guilt about depression 😢

Hey guys.. I have the sweetest 2 year old daughter. She is such a happy, fun loving girl. She is always trying to get me to play and cheer up. Im a stay at home mom right now so its just us all day. I love her so much, but lately I've been feeling really depressed. I have so much guilt about feeling this way and feeling so negative even when I'm around her. I always get excited for bed because I am able to just be alone for a little and not have to stress about putting on a happy face. I feel absolutely awful that I feel this way. I am angry at myself for being so depressed when I have the best thing in the world right there with me. I watch her smile and get excited, into whatever she is playing and I just want to go lay in bed. It breaks my heart, because I so badly want to feel good and want to feel like playing with her. Any advice??