Sleep regression in my 5 month old, please help!?

My son is 5 months old and has had a stuffy nose (no other symptoms) for almost 2 weeks now and his sleep habits have gone haywire. I can't remember when it all started so I don't know if it's related to the stufy nose or not. Since he was 2.5 months old, he has slept 7-7 consistently, with 2 1.5-2 hr. naps during the day. He was able to get himself back to sleep and go to bed awake no problem. Now, he wakes super early (between 4-6am), wakes up after 40 minutes in a nap and cries and cries and can't get himself back to sleep. He is noticably tired and just fights it. But I have no idea what is going on, his sleeping patterns have regressed to what they were like when he was 2 months old. Now he ends up waking from a nap so early, that by the time he needs another feeding, he is ready to sleep but too hungry, then once he eats he goes right down to sleep. I don't want to start that habit! And he doesn't like to be alone and wants the pacifier more. He used to be independent...help!