Hi there,
First off, big hugs to you! I completely understand what you are going through. I went through this with Brendan, who started catnapping when he was 7 weeks old. It was crazy, frustrating and exhausting!
What I learned from the whole experience, was to just concentrate of learning how to fall asleep-- focussing on sleepy cues, and settling to sleep. I kept the awake time short, made his sleep environment dark as possible, swaddled him tight (some of my friends swear by the Miracle Blanket and the Aussie Swaddle) and helped him settle to sleep. He would always wake up at 45 mins.. either wide awake and happy or he would be screaming. If he woke up crying, then I would try to resettle him to sleep.. I would go in early to anticipate the wake up. If he woke up happy, then I would do a quiet activity and within 10 mins. he would be yawning again, and I would put him back to sleep.
To be honest with you, I found it hard to resettle him to sleep, so I would take him out for a walk or lie down with him. Since he was a young one, I knew that his ability to self soothe wouldn't come start to develop until after 3 months-- so I did relay on some props and "accidental" parenting to extend his sleep. But when he was past 3 months old and he became better at falling asleep independently, then I changed strategies.
There is a thread here under Announcements called "Newborns and sleep" and in it are some posts about jolts. overtiredness and getting past the 45 min. mark.
Hang in there.. I know it's frustrating, but it will improve. It's mostly developmental, and will be something your little one will get past between 4-6 months of age.
