N.M.
It's wonderful that you are working so hard to keep up breastfeeding. I remember how hard it was at first!
I recommend the Lansinoh lanolin ointment, too. It will really help heal the cracking and relieve that pain.
Also, it was a tremendous help to me to have a feeding schedule/routine. (I don't know the term "block feeding" but maybe it's the same? The book I read called this "parent directed feeding".) For instance, on a three hour schedule, I would feed my daughter at 7 am, 10 am, 1 pm, 4 pm, 7 pm, 10 pm, and overnight only if she woke up hungry. It was a real benefit because I knew when my girl would be hungry and could easily schedule trips to the store, and if she were fussy at, say, 9 am, I knew it probably wasn't because she was hungry but more because she needed a nap. When my son was very small, I tried a feeding routine, but I didn't understand it well enough and had a lot of trouble getting it to work. But by the time my daughter was here, we had it down pat.
The key to getting on a schedule is to feed at the scheduled time even if the baby isn't fussing for food yet. You can give or take a few minutes of course, but I wouldn't vary the time more than 15 minutes. The ideal routine for is blocks of "feeding - awake time - nap", and repeat through the day. (The exception to this would be our 10 pm feeding, afterwhich I would put the baby right back to bed.) When you realize that the baby is routinely sleeping past their feeding time, then you know you can redo the schedule to 3 1/2 hours or even 3 1/4 hours. When my daughter was about 8 months or so we were on a very convenient 4 hour schedule, the ultimate goal. (For us it was, 8 am, 12 noon, 4 pm, 8 pm. It was able to transfer very nicely into breakfast, lunch, snack, and dinner.) One more thing about schedules, babies periodically have growth spurts when they need to nurse more frequently. So we would adjust out schedule to maybe 2 1/2 hours for a few days to accommodate.
Here's how you might get a feeding schedule started with your son. First take a day or so and write down the time each time you nurse him. Then look for a pattern. Perhaps he is usually wanting to eat every 1 1/2 hours (look for an average interval). Then set yourself a starting time in the morning, let's say 7 am, and write down the times you will feed him during the day. At 1 1/2 hours that would be 7, 8:30, 10, 11:30, 1, 2:30, 4, 5:30, 7, 8:30, and 10 (since he's not a newborn, don't worry about feeding overnight unless he wakes up for it). Then try it. If he starts fussing for food at 8:15, commfort him or play with him to hold him off until 8:30. If you're at the store at 2:30, find a place to nurse him (I always parked at the back of the parking lot so I could go to my car for some privacy). If he's sleeping at 10 am, wake him up and feed him anyway. I know that kind of sounds counter productive, but the idea is to get his little stomach to regulate itself to be hungry at regular intervals. Try really hard to keep as close to the schedule as you can at first, and as his digestive system gets more regulated you'll be able to be more flexible. Start at the same time every morning--if he is sleeping at 7 am, wake him up, or if he wakes up at 6:30, try to keep him busy until it gets closer to 7. After several days, he should become accustomed to the routine and you might try stretching it to 1 3/4 hours. Before long, hopefully you can get to 2 1/2 hours and then you'll have some more freedom in your day.
Hope this helps! Write anytime if you'd like more info on our feeding schedule. Good luck!