The battle of nap time

So

I have a 5 month old son who has become clingy ( I don’t know what other word to use) I can no long transfer him from feeding to crib when he falls asleep nursing. [This is a nap time problem during the day] I can place him in the crib for all of 5 minuets before he wakes up crying to be held. Once someone is holding him he goes back to sleep. I have tried cry it out with no progress. I’ve tried sleep training but he never took to having a schedule. The only time he stay in his crib for extended time is for bed time 9/10 pm (due to our nap struggle during the day , he fights to stay awake. I try to put him to bed at 7 pm but he fights it. ) until 4/5 am then he goes back to sleep until 9/10am and stays awake all day (except when I give in and let him nap in my arms). I need suggestions as to how to get my son to take at least one nap during the day. According to all the articles I’ve read he should have three naps during the day (I guess his sleep from 5am-9am is a nap ).