Unfortunately, I don't think I have any advice, but just a similar situation if that helps you feel better. My son's feeding schedule seems almost identical to yours both past and present. We are also having a wide awake 3 or 4am waking that currently on a good night lasts 45 minutes and more like an hour on a regular night. Same thing, not fussy, just awake and ready to tell me all about his dreams and ideas for the day to come! I try to limit eye contact and don't talk to him, and just pull any trick out of my hat that usually helps him go to sleep. The one I like the best is Dr. Karps soothing techniques that are really suppose to be for birth to 3 or 4 months, but they work like magic with him and they are the only way I can get him to nap right now. It is the 5 S's. Swaddling (which we only do at night, but he still wakes without it), Shhing, Swaying (or rocking or bouncing, whatever he prefers), Side or Stomach placement (it is more soothing than the back position due to the Roto reflex (I always forget if I call that the wrong thing. It is the jerking reflex they have when they are infants, which my son still has and that is why he still needs to be swaddled), and Sucking. We have found that our son likes to snuggle with a soft "lovey" blanket that he likes to be over his eyes and he sucks on this since he won't take a pacifer. We hold him tummy to our tummy, with his head on one crook of the arm and his bottom on the other and we bounce up and down while we make shhhing noises. Works like a charm. With the body placement, you can hold their arms and legs pretty tight so it gives the effect if they are not swaddled. We just read his book, "happiest baby on the block" 2 weeks ago, and since he was a fussy baby due to his tummy pains (that developed into reflux), I had wished I read this book earlier. But anyway you can try that and see if it puts him to sleep any faster. It also works wonders if they are overly tired and fighting sleep.
Also if he is on breastmilk, our gastro specialist just told us that breastmilk has 20 calories per ounce, and cereal since it is starch has 23 calories per once. So she said medically that is why research does not support that it helps them sleep better through the night. We are waiting until 6 months to start cereal at our doctors request because current medical belief is the earlier you start, there is more of a possibility that your baby might develop food allergies. But some of my friends doctors told them to start at 4 months. So obviously doctors are not unified on that belief.
Hang in there, and know at least you are not alone :) My husband and I have also started taking turns so we both don't end up loosing sleep every single night. The other one of us sleeps in our room with a sound machine on and the monitor off, while the other one sleeps in the guest room or on his twin bed in his room. That has been necessary for my sanity lately since I have found out I don't handle sleep deprivation well.