going outside would mean making your breasts fill up with milk. you guess you could keep milking yourself outside though you are sure you couldn't keep up with it. probably some machinery would help with that and something to at least filter a bit of the air like a gas mask. you could get that from some stores in town which hopefully aren't over run too much. you look at a map on your phone. it's a little walk, but it should be doable.
you take some cloth and wrap it around your moth and scuba glasses. you contemplate if you should expose your breasts as you will need access to them but decide to at least put a hoodie that you can unzip. you quickly run to the store.
while running you breasts quickly began to swell. you managed to get to the store though your breasts had already swollen to unmanageable size. you milk them inside the store and managed to get them to small D's you quickly search for the milking stuff and some food, water and other stuff and shove it into your bag. as you leave you hear creaking from the above and the store collapses as a person swells from the floor above. in horror you watch it happen to some other buildings too. you quickly retreat back. luckily you live in a separated building. you gawking at what was happening had it's disadvantage, at your doorstep you could barely move with as your mounds had swelled to much. you milk them again but barely managed to get yourself light enough to move yourself inside the house. you pass out.
you wake up lifted up a bit up front. you see two fleshy sphere of a meter in front of you. you try to get to your nipples, but they are just out of reach. you drag yourself in a position that your nipple will be squeezed by a door just barely are able to hold the door. you milk your breasts to a size that you can move to the bathroom and finish milking yourself. you thought it would get easier, but even when you were outside trying to get the stuff, while milking you were aroused, which bothered you a bit.
you finish and look at what you managed to grab. you found some electric breast pump. you think you could make them work a bit faster through some soldering.