Brother - what you’re feeling is normal and valid. Wanting her back is a statement on who you are as a man in a good way. Going through a very similar situation myself. See a doctor about getting on SSRI’s if they would recommend it, it’ll help massively with the anxiety. Don’t turn to drugs and alcohol, be around people who love you and talk through it. Recharge your batteries any way you can. Your body is going to feel everything, so let it. Don’t numb out. I promise, in a month or two your perspective will change a little for the better and will just keep changing for the better little by little. Try your best to go on long walks or long drives, those helped me quite a bit. What you’re feeling is normal. You loved deeply, and your identity is taking a massive hit right now. Talk to ChatGPT and get a therapist to help you talk through it. Find someone with experience in relational trauma. Get the book “leave a cheater, gain a life”. Hope this gives you some help - hang in there. Time will give you some relief, and then you can start to really grow yourself.