If you feel you cannot keep yourself safe and may harm yourself, go to A&E. If you are safe then ring Samaritans or other helpline or talk to us here until you can get a GP appointment in the morning. Be up front with the receptionist, tell her you're having a mental health crisis and you should get a same day appointment.
Make A&E a last resort as its not the most restful environment for someone in crisis and if you'll excuse my putting it bluntly, it tends to be more of a holding cell. Once you're there you will likely not be allowed to leave until you have been assessed. You will be bottom of the pile as you are technically now safe and do not have a limb hanging off or raging septicaemia. And those chairs are awful to sit on never mind sleep on.
They may have a psychiatrist on call but may not and they tend to basically just keep you there until you're too exhausted to be a threat to yourself then release you with a crisis number to call and a referral that can, in my experience, take up to a year to get anywhere with. A referral that your GP will give you without putting you through the trauma of being detained at A&E.
Having had experience of it myself, I would not recommend it. 0 🌟 would not stay again. Not unless I was at the point of actually killing myself.
I know it feels so so urgent right now but you have to push through it and remind yourself you don't have to do anything right now. That was my mantra. You don't have to hurt yourself, you don't have to be ok, you don't have to take charge of the situation. Just sit with it and it will pass.
You can message me if you want, if it will help to talk to someone who gets it. But get that referral to mental health services or if you can afford private counselling, I wholeheartedly recommend it.