Hey C.,
So, I read this and thought, "Oh my gosh, that's me!" I've thought about posting this very question over the past few weeks, but things have gotten better here so instead I'm able to pass along a little advice to you.
My son will be 4 months on the 29th and had been doing the exact nap schedule that you're talking about. I'd feed him, rock him, put him down and it'd be 20-45 mins later and he'd be crying. I'd pick him up and often times he'd fall right back to sleep on my shoulder. I finally went to the pediatrician who treated him for acid reflux. He started taking Zantac and things got a little better. He'd have some days where he'd nap for 2 hours and then there'd be days where he'd nap for 20 mins several times a day and some days, he wouldn't nap at all! Night time was the most difficult though. We'd start the bedtime routine anywhere between 7 and 8 and by 11 we'd finally have him down for the night. He'd go a 4 hr stretch, then every 3 hours til morning. I was growing more and more tired and more and more stressed out. Here's what I've done:
Stopped nursing him to sleep when possible. Obviously, this isn't possible every time, but when I notice signs of tiredness, I put him down.
He is swaddled and sleeps in his carseat in his crib. I know, sounds crazy and I'm sure plenty would disagree with this setup, but it works and I'm gonna do what works right now!
At night and sometimes before the expected long afternoon nap, I bottle feed him his breastmilk. This way I know how much he ate prior to going down and I can rule that out of his reasons for crying. At bedtime I have started giving him 4 oz of formula also. It seems like I can't pump enough milk for him at the end of the day, so this is what we do. My husband does the nighttime routine and he first gives him the formula, then a bath, then the breastmilk (usually 3-4 oz) and by this time he's asleep and done for the night. Most nights he down by 7:30 and doesn't wake again til 4 am!
When he does wake up 20-45 mins into nap or bedtime, we let him cry for 10 mins. This is my max amount of time I let him cry and believe me, it seems like an eternity. I understand some don't like to do this, but again, it's what's worked for us. He normally will cry anywhere between 2 and 10 mins and his naps have lasted as much as 3 hours! We do still have some really bad nap days, but I guess at only 4 months we can't expect every day to be a good one!
Altogether, I believe what's helped us the most is the sleeping in a more upright position in the carseat and letting him cry for a few mins. I've read that babies will wake at times during their nap and just don't know how to get back to sleep on their own. This would be especially true if they are nursed to sleep.
I really hope some or all of this will help you. I was at my wit's end with the short naps! I have a 3 1/2 year old also and was just so completely worn out by the end of the day that I just wanted to leave once my husband got home!
Private message me if you're interested in talking more!
S.