The crying out method has actually been shown to create many emotional problems in young children due to the fact that these poor babies are scared and screaming for their parents (distress) - when the parents don't come the child feels even more scared and abandoned (despair). Over time (those several horrible nights) Then they simply give up. They have learned that when they need you you will not be there.
The other reason cry it out methods are not good is that it is not healthy for the babies bodies. The intense screaming and crying leads to blood pressure rising - pressure in the head also rises - there have been cases of babies have brain bleeds as a result... I fail to see how anyone anywhere can believe this is a good thing and that the importance of making a child independent is worth the risks to a child's sense of trust in his parents and his health. The intense panic attacks you describe worry me - I'd advise that you do not ever let this happen again - it is not healthy for your child in any way.
So you are worried about bringing your child to bed. Why? He will go to his own eventually. :) Right now you will all get more sleep - your son will feel safe and loved, you will know he is safe - you all get sleep - what is the problem?? Co-sleeping (or in this case, Co-Bedding) has been shown to be a healthy way to raise a child. Not all children and parents can co-bed (I couldn't co-bed with my middle son - he kicked too much!) but they can co-sleep - which is simply sleeping in the same room.
If you are fine letting him sleep in your bed - go for it! It is wonderful, warm and snuggly - it will leave you with many warm memories of waking in the morning to a sleeping child - or even better - a child who greet you with a BIG smile! If it is hard for you to have him in bed (for whatever reason) bring his crib into your room and let him co-sleep. If he sees you there, he may very well be just fine.
Now, regarding the length of time he sleeps. This is normal. I know it is a challenge, but not all toddlers sleep for 12 hours at night. So, by simply understanding that he is sleeping in his own normal sleeping pattern...it will help you at least to ease the frustration. If he will sleep longer by coming into bed with mom and dad when he wakes up early, then bring him into bed. You will get more sleep and so will he.
You said you work full-time. Many kids will need to stay up longer to be with parents - to reconnect - after mom and dad come home from work. Babies in full-time day care spend the bulk of their awake time with people other than their parents. They NEED time with their parents - so they take it when they can. This is normal...
I wish you luck. I've been there...I finally just let my kids sleep with me (except #2 - he slept near me) because I got better sleep and so did they. I learned very quickly that it was a wonderful thing and actually suited me and my (then) husband. Our children are very happy, healthy and independent. :)
Take care!
J. Simpson, IBCLC, CIIM
Lactation Consultant