Called in and told boss I blew off my hand with firework last night (a lie) now need legit sounding reason for why I have a hand again on Monday

I think a good thing for you would be to admit that you over exaggerated in your text, or that you meant to say something else and jumbled up the words.

The best thing to say is the truth, that you sent a drunk text.

I have to say, work history is not looking very good for you.

I really, really would not recommend that you come into work with a bandaged hand just so that you can keep up this lie. If you do typing, your work productivity will be slowed down, and if you do any sort of manual work with your hands, the bandage could be a hazard, especially with machinery around, there are so many ways to legitimately lose a finger, an arm, or your life, and bandages and long sleeves and lack of protective equipment are a great way to lose your limbs. So I am fearful that coming in with this bandage will just set you up for even more misery and even more lies.

I understand that you feel shame. Lying to hide your shame just makes more shame.