As PP said, it happens to almost all of us at some time. Feels so horrible to be in it.
Here's a fun challenge - it got me out of a similar identity crisis/low energy/low motivation rut.
Do something you have never done before every day for a year. get a nice notebook or open a private blog or file on your laptop or phone to record your experiment.
Start small if you want - different foods, soaps, drinks, routes to school, work, home etc. Play artists/songs/music styles you don't know on Youtube or Spotify; tune into a radio station you have never listened to before, do an online yoga/tai chi/HIIT/bodyweight workout. Build up to easy but slightly more challenging stuff - maybe visit a local landmark or beauty spot, gallery or museum; try a new physical activity like kayaking, paddle-boarding, wild swimming, jive dance, rock climbing etc.
You might want to do easy things during the week and harder things at weekends. Record each activity with a note about what you felt about the new things during and afterwards. Anything you like, try to incorporate it into your life, or try other similar things.
Another helpful thing to try is to divide life into 9 categories: Home, Family, Finance/Work, Fitness & Health; Community/Society; Friends; Fun; Spirituality; Education, Romance etc. You choose your categories - the only one that has to be included is Community/Society. Then you do one thing each week to improve that thing in your current life. Home could be tidy or declutter or redecorate or reorganise; Family could be taking child to park for picnic after school or going to visit a relative you like. Community is contributing in some way to the wider world - through charity or activist group or church etc.
The theory is, as you develop each of these areas, your life becomes stronger and more rewarding in every way. Then if one aspect of life, or even two or three, all collapse at once, the other aspects are thriving and help you through. Again, you just keep a record in a notebook or online file on what you do each week. After a few weeks, you start to feel better.