Baby falls asleep..but i cant! HELP

please mommies any advice is welcome. my baby is 4 months old on Monday and I proud on how far we have come sleeping wise (for her) She is able to go to sleep more hours through the night (she still wakes up every 4-4.5 or 5 hours if I'm lucky) and I don't really have to rock her to sleep any more. She is able to fall asleep on her own after talking and playing by herself for 5-10min. It would be great and everything except here I am awake every night EXHAUSTED. I am tired of crying because I can't get any sleep. I toss and turn literally for hours til baby wakes up for a feeding. I already know when she is about to wake up so I go fetch a bottle. I am not sure why this is happening but its been going on for 2 months and every day I tell myself I will get a good nights rest but I don't. By the time I fall into a deep sleep it is already 7am and baby wakes up at 9am to feed so again I get up and make a bottle then back to sleep at 930 and I wake up at 12 then get my day ready. We co sleep together but I don't think space is an issue since I was able to sleep 2 months ago. I don't know what else to do, I would love to sleep through the night so I am able to get up early to start the day. I am tired of feeling tired. Anyone has gone through this?