Oh boy girly. . .that's alot!
I too like lansinoh but I am really a big fan of something called smoothies. They are gel like things and you put them in the fridge and then wear them in your bra. It keeps the material of the bra from rubbing against your nipples. I wouldn't ditch the lansinoh but the soothies will help you feel better.
Regarding the yeast--this you need to get on top of immediately. If the baby has yeast in his mouth, then the yeast will enter through the crack of your nipple and you'll think that having cracked nipples is like eating candy. A thrush infection in the breast is very, very painful. I will second the advice on eating yogurt daily and in fact, in your case because your nipple is cracked I'd say eat it at least twice per day. However, if you start to feel a burning or stabbing kind of pain--you need to get your doctor to prescribe an anti-fungal and NOT an anti-biotic. The sooner you deal with it the faster it will get better.
Regarding the cracked nipples--this is always related to latching problems. Either the baby isn't latching on correctly or he's not latching off correctly. You need to fix that. I can help you figure out what's going on more later. Just be aware of it. My first suggestion, since it's just one of your nipples, is to hold him in a different position to nurse on that side.
Regarding increasing your supply with galactagogues. Yes, you can do that and yes, it works. However, I would strongly recommend that you deal with the issues that are leading your supply to be lower rather than doing galacatogogues. There's no harm in them. . .but you don't "just have a low supply". Given that you have a cracked nipple, I'm guessing that something in the way the baby is nursing is not going right--and that has to be fixed. Otherwise you can take them until you're blue in the face and it won't help. They have to work in conjunction with a good latch. Make sense? Also, if you're not working on that latch issue, then you are likely sabotaging yourself by increasing your supply--if you give me more details we can talk about this further. HTH