Oh love, I could have written the same post a few weeks ago.
I'm not going to sit here and tell you that it's completely normal, because that is not what you need to hear. But please rest assured, it will get easier really really soon. My DS is 6weeks old and in the last 1.5 weeks has somehow just become easier. I don't know how, it's sure as shit not anything that I have done, but it is getting easier.
I stopped breastfeeding at 3.5 weeks, because honestly, fuck that. I know I will be lynched by the breast is best brigade, but it literally takes everything out of you and sleep windows do tend to be shorter for Bf babies. So if you are able to, I would recommend formula, it has saved my sanity.
I was dealing with the 2 hour stretches of sleep at 4 weeks, and then 3 nights ago somehow the stars and moons aligned, and my baby slept for a 5 hour stretch.
5 hours!! And the next night he slept for 6 hours. Last night he was back to 3.5 hour stretches but just having those couple of nights where it was a longer period was like a light at the end of the tunnel.
You should get smiles in the next couple of weeks which I promise will make life easier.
As others have said, if you can get help please do. My best pal turned up after I had a colossal breakdown on the phone to her. The angel came over and watched the baby, let me sleep. She stocked my fridge with food and she brought infacol, gripe water and a million extra muslins. Stuff like this will help you no end.
If you have a partner, can you get him to do one of the night feeds? If so, stick some ear plugs in or bugger off to another room for a bit to catch up on sleep, even if it's just a couple of hours uninterrupted sleep it will help you no end.
At this stage you just need to survive. The overwhelming feelings of panic / regret will ease. You are probably still in the thick of the baby blues with hormones rushing around so go easy on yourself.
Big hugs, it is the hardest job in the world xx