He is still VERY young... they are still adjusting to daylight/nigh-time....for our daughter who was like that... she had bad gas problems, and it would always seem to bother her more at night. We gave her infant gas drops which helped. Our daughter rarely farted... and I think she had extra "gas" accumulating in her intestines...
There is also something homeopathic called "Hyland's Colic" tabs...BUT, it's NOT only for colic...it's for any gas/indigestion/sleeping upsets in a baby... and helps to calm them. There are no contraindications and it is not habit forming. YOu can look it up online and see reviews. This also helped our daughter.
It will pass though... their internal organs & neurological system are still developing outside the womb... and it causes discomfort... also, maybe something in your breastmilk is making him gassy??? This often happens too.
Mostly, gas causes a LOT of pain in babies... sharp pains. I wouldn't be able to sleep with that either, and I had that after I gave birth. It's sore.
Other than that... he is cluster-feeding now... so that means he is either having a growth-spurt...OR, that he is not getting enough intake....and so by the time night-time comes....he is simply totally hungry & starving. This also happens and had happened with 2-3 of my friends. You should check that he is latching on well and is actually suckling...
But this "witching hour" is one of the rites of passage that we have as Parents. It just happens.
For some babies, they must have absolute silence to calm down. For others, "white noise" helps them. For others... they are simply TOO "over-stimulated" and it gets them upset...hence crying constantly...**in babies, "crying" is ALSO a way to shut-out external stimuli as they TRY to tune it out. So, keep that in mind.
As for how long it lasts... every baby is different. For my daughter it lasted about 6 months.
Whatever you do... do NOT just let him "cry-it-out." He is just a newborn...and crying it out even changes their brain chemistry. And, it will not allow them to "bond" as they should.
Carry him, comfort him, help him cope. They are helpless.... and they need to bond and feel secure.
You could also try and "swaddle" him for bedtime. This helped our daughter too. As an infant, their limbs "flail" and this wakes/disturbs them too... as they cannot control their reflexes yet. It takes time for them to outgrow this.
A great book is: "Secrets Of The Baby Whisperer- how to calm, connect, and communicate with your baby" by Tracy Hogg.
All the best,
Susan