I don't have a lot of advice, but what I can say is, yes, a 6 month old is a baby and can't be spoiled by attention. But, there's nothing wrong with training your baby to put himself to sleep.
I know it's hard letting him cry. However, it is a way to train him to soothe himself. After laying him down, wait one minute then go in a check on him, reassure him that he's okay. The next time, wait 2-3 minutes. Each time, increase the time between your visits. After a few days, you should see an improvement.
Our daughter now may lay awake in her crib for an hour or so at night, but she can put herself to sleep.