is it selfish to stop breastfeeding?

Ultimately I know it's my decision to make but I want to know your thoughts and what you would do.

So the situation is this, my daughter is currently 4 months old and I've been breastfeeding since she was born. In short- it's been my own personal hell. For the first month I cried though horribly painful nursing sessions, then dealt with mastitis. After that I finally got to the point where I was saving a little bit of milk and then I got the flu, went from making 5 oz to 1 oz a session and had to supplement formula that week. Which was so mentally taxing in itself bc you know how much formula is shamed... it's just been really hard and I feel like I'm at a decent place now and I'm happy with myself for overcoming all those issues with breastfeeding. 

A little background info before I get to my question... I've had giant boobs since puberty. I mean literally they like grew overnight from nothing to D's. During my pregnancy I went to a  DDD and now I'm squeezing into an F. If you share the same struggle I don't have to tell you how hard it is. I have no self esteem left, I can't find anything that fits me so I always feel frumpy and fat, they give me back pain that radiates to my neck and gives me tension headaches and I'm just so generally sick of them. I know that eventually I will get a reduction.

Now onto the controversial part, my goal that I set when I was pregnant was to breastfeed for 1 year. Is it selfish of me to stop at 6 months and start preparing to get a reduction now? I go back and forth on the decision all the time and it always ends in tears. On one hand I want to breastfeed and do what's best for my daughter but on the other hand I don't want to remember the first year of her life as just miserable for me. I'm also going back to school full time in the fall and I don't know how I would continue to breastfeed because I will be away from her for two days a week and I haven't been able to get a stockpile because I only make what she eats- nothing extra. My MIL has told me getting a BR is selfish and I should keep breastfeeding. I kind of agree with her. What do you think?