What's reasonable?

My (loose) goal is to provide breastmilk until month 6. During the 3-4 months I'm on maternity leave, how much of a freezer stash could you build up? The sooner I can dry up/stop breastfeeding and pumping, the sooner I can take some antibiotics (6 weeks worth!) to clear my skin of a rare skin disease that I came down with last July. It causes dark brown/reddish scaly patches on my trunk region and my underarms, back, stomach, and chest are totally covered in these patches. Some are light and some are dark, and it's totally benign, but some areas are getting darker and I'm embarrassed to wear anything without sleeves now because they are SO DARK under my arms My skin is very speckled....in the winter, I could hide under more clothes. But spring and summer are coming and I don't want to look like a leper!

I figure my options are:

1) pump as much as possible and use it until it's out, then go to formula

2) Hope the intensity of color fades post pregnancy (probably won't...the dermatologist said pregnancy has zero effect on it)

3) pump as much as possible and give pumped milk and formula, spreading out the pumped milk.

4) deal with the awful skin until the fall, then start antibiotics

I don't know what to expect and pumping could go well or it could not...