R.D.
The guilt of going back to work versus the guilt of not being able to provide for your child... put it into that perspective ;) It's the QUALITY of the time you and your kiddo spend together, not the quantity. You're giving your child a very valuable gift of not ever having to want or need anything by working... the flip side, is not having enough food or clothes and being miserable, and having a miserable parent as well. You're doing the right thing!!
Be confident when you go back to work, and he'll be fine too. Every kid has to go to school eventually! Mentally prepare BOTH of you, and get him excited about making new friends and learning new things at daycare :) TONS of parents do it, and you'll both be fine too :)