The weeping daily thing is rough.

My therapist encouraged me to lean into the pain which seemed insane at the time. Apparently one of the best ways to get over it is to go through it. Many of us end up in codependent relationships because focusing on the behaviors of others keeps us from feeling our own pain. That pain feels unbelievably heavy but kind of like exposure therapy there comes a moment when it's almost a relief. I can't believe I'm saying this but I sometimes miss how raw things felt. After being numb during much of my life I was unprepared for flooding emotions. My T also said the phrase pain x resistance = suffering. Let yourself cry. There might even be some relief there.
Also, 12 years is a long relationship. It wouldn't surprise people here if it takes you roughly 2 years to get back to something even better than what you had before the relationship. I was married 10 years and it took 22 months to heal. If you told me a few months into post-divorce that I would meet and marry my current husband, a lovely kind thoughtful generous funny smart man with shared values (and a BPDx of his own), I would've never believed you. In the early days after my divorce I would weep silently while walking my dog, unable to place exactly what the sadness linked to other than feeling like I was a giant nothingburger.
You get to be a mess right now. It would be weird if you didn't need some time to sort things out and regroup. Cry it out if you need to. Those feelings want to see the light of day so they can dissipate and lighten your soul.