Echo the above replies, Ralphy. Get yourself booked in to the doctors as soon as you can.
But this app may help; the Hub of Hope. Gives you info on local support based on a postcode or your current location; if you’re doing long walks that take you away from your home and you suddenly need support it may be handy. It also has a 24-hour text service. From what you’ve described with your erratic sleep pattern/early morning walks, it may be of use when you’re in need of some contact when everyone you know is in bed. Mental health issues can feel like they’re excruciatingly worse when you’re facing them in the darkened hours. I’ve used the text service a few times and it’s not a bot or automated reply, it’s an actual person on the other end. Just getting a few back-and-forths going can help, even as a distraction.
But again, please get yourself to the doctor if you already haven’t arranged an appointment.