A massive happy Birthday to you Lonely mummy !!!!! I know you are feeling crappy but hopefully a birthday cheer from a stranger might lift you a bit.
If you have no energy to go out , i would stick me earphones on and tune out a bit but not too much so you can here your 2 kiddies . Or give yourself a nice tummy and back massage . Or stick a chair outside and catch some rays ? Or eat some chocolate ? Its your birthday afterall
Hope you feel better soon x