Hi there,
I'm sorry, I don't have any answers, but just want to say you're not alone!! At 7 weeks old, my little guy would sleep from 6:45pm-5:15am, I would feed him, and he would sleep again until 8am! Then he hit the 3 month growth spurt, where he woke up 5-6 times a night for a week. Since then, he still only feeds once a night, but will wake up 2-3 times and often need help to get back to sleep, and wakes up at 5am-6am! Uggg! So frustrating!!
I read an article about "sleep regressions" actually being "growth progressions"...when little ones have physical, emotional, intellectual developments etc, it affects their sleep, but they will go back to normal after the development is over. Reading this article helped me a lot, it changed my perspective to see it as something normal that is required for him to grow and develop!
Hope this helps a little!