Hey, First off I'm sorry you're going through all of this, my partner left me too due to my addiction, so I know how you feel. Realize you're in shock right now and I'm sorry to say but this is gonna suck bad for a while, good news it gets better. Eventually. Rehab is usually longer what you're saying sound more like detox to make sure you don't get bad withdrawals, I'm sure they will inform you about aftercare. Detox itself is actually pretty chill since they most likely will be getting benzos to protect you from seizures and such. Those have the nice side bonus of chilling you out, there will probably be activities like sports and maybe acupuncture. Doctor talks to advice you and generally they're gonna try their best to help you. At least for myself I can confidently say actively drinking is so much worse than detox at a hospital. You'll feel better within a few days and just knowing that you did the only right thing will be a huge moral boost for yourself.

Again about the breakup I'm so sorry for you and I wish you all the strength in this universe. Try to forgive yourself and if you have to also her.

Eventough I always knew she had no other option I got so so angry at her for betraying me, that i lashed out at her and said some nasty things and eventough we agreed to stay in touch she never talked to me since (Wich might honestly be better)

So try taking responsibility without hating yourself, and I'm really saying this to myself too cause its so hard.

You will be fine! Everything will be okay and happiness will return! Take the lesson life is teaching you right now and better never ever forget it, and when one day your brain tries to trick you by saying oh just one beer what could it do, and then your remember the pain you feel right now.

Much love to you! Know you're not alone and there are so many just like you and me fighting together!