I'm so sorry.
My 2nd baby went through a period lasting a month or two where he would be awake, usually crying, sometimes screaming, from about 10pm to 1am or even 3am. I think we finally decided it was gas.... but it was absolutely the most exhausting and emotionally trying thing we've ever been through, probably .
If the crying like that starts repeating for you, and you suspect in might be gas, I'd really make sure you're familiar with infant massage techniques, etc. to help relieve gas, and maybe look into getting some gripe water, as well. And if it's just a matter of nights and days confused a bit, I hope you can figure it out quickly.... because I didn't, back then, but sure wish I would have been able to!!