Sounds pretty normal to me, since my three boys were all rather high-need. The good news is your sensitive, responsive mothering will help him become a sensitive, thoughtful person who connects well with people. This is an investment period in your relationship with your son and also in his development--it won't always be this intense!
I, too, recommend using a sling. It's like having a third arm! I like my Maya Wrap ring sling, but I know some moms like their Babyhawk mei tai carriers for longer wearing time.
I also suggest attending a La Leche League meeting in your area, since those moms tend to be responsive to their babies and can offer lots of gentle suggestions (and coping ideas) besides "cry it out." Also, LLL groups have lending libraries of gentle parenting books and you can borrow some good ones. All their services are free.
My favorite baby care books, hands-down, are "The Baby Book" by Dr. William and Martha Sears and "The Happiest Baby on the Block" by Dr. Harvey Karp. They are both reassuring and helpful. Sears talks about doing the "limp limb test" and lifting an arm or a leg of a sleeping baby before trying to put him down. If he flinches, you know it was too soon and he wasn't in a deep sleep. If his limb is still totally limp, you now he's out and you've got a good chance of putting him down. This technique has saved me many fake-outs and wasted efforts of putting him down. Also, (some may not agree with this, but my babies and I are all well-rested) I like to nurse my babies to sleep in my bed, laying next to them. Then I can get up and peel myself away and Baby can stay comfortable right there without me having to move him. It's easier to peel away from next to him on a bed than from under him holding him in a recliner. . . I also leave the bathroom fan on for white noise to keep him sleeping. Dr. Karp's book talks about using white noise to help babies sleep.
My first two boys were not great nappers, but have grown into good nighttime sleepers. Hang in there!