Need to wean but no idea where to start

My daughter has been EBF and is now 13 months. She’s good with sippy cups and will drink whole milk but still prefers boob. I’m a stay at home mom so she’s used to having it on demand. She will nurse basically any time she’s bored when we’re home and before naps (not that she’s taking them anymore) or bed. She still wakes up during early morning hours and I’ll nurse her back to sleep. I’m at my wits end I need my body back and I need to get back on medication. I have no idea how to wean her when she’s still nursing this much. I have PPD/PPA as well as mental health issues I had prior to pregnancy. Her demand for boob is contributing to my poor mental health but I also can’t stand to hear her cry and I know the guilt is going to kill me. I guess I just need any advice or even to hear what others experiences were like so I know what to expect.