Pooping every three hours or every three days or even once a week is perfectly normal for a breastfed baby.
If she is tongue-tied, it may be contributing to the gassiness, BUT it may also just be normal development of her digestive tract. Most babies have a "witching hour"...you just got unlucky with the timing on yours.
Have you also eliminated milk from your diet? I noticed a drastic improvement when I did...slowly started adding it back in around 4 months. It takes 2 weeks for the protein to clear from your systems, so don't expect drastic improvment before then.
If it is a regular thing, I would suggest (trying...lol) to wake up and burp her before the screaming starts. It will be easier on both of you. Good luck. I won't say it gets so much easier...lol...but it does change.