M.C.
People can share their schedules, but every nursing relationship is different--every baby is different. Every mom's milk is different. How often and how long your baby nurses depends on many factors. It depends on your baby's particular caloric needs, and the caloric value of your particular milk. It depends on how much milk your baby can comfortably hold, and on your baby's particular digestive system (how fast your baby digests your milk). And there is also the question of how much stimulation you need to maintain your milk supply. So what works for one nursing couple may not work for you, and you will end up frustrated.
You will be going back to work, and I assume you will be putting baby in daycare? What I found was that when I started getting up every day at the same time, and waking baby every day at the same time to nurse in the morning before leaving, baby settled into a very regular routine of his or her own. This happened with both of them. So, I suggest this as the first step--make your morning routine match what it will be and see what baby settles into.
Your baby has obviously settled into a regular routine. If you start your day at the same time every day, you will probably find that it is actually a pretty regular schedule. You already have the schedule that will work for you and your baby.
Your baby probably needs to nurse as many times as he is, and he may continue to need to nurse that many times even up to a year. But if he'll take a bottle, a breast-feeding friendly childcare provider will understand that and will offer the bottle at the necessary times.
Because of the timing of your return to work, it may be helpful to be reminded that babies typically go through a growth spurt right around the 6-month point. So right when you're going back to work, your baby will suddenly begin needing to nurse more often and for longer periods as he tries to stimulate your milk supply. If you can get that growth spurt out of the way before you go back to work, it might make the transition a lot easier.