What would you have done?

I got dropped off in the driveway with my 1 month old baby, by a friend who took me to a Dr appointment. My 6 year old gets off the bus in 20 mins, Its 38 degrees where I live today. I let my brother and his gf come live with me because they have nowhere else to go, they help out a little bit with bills, but theyre slobs and make alot of mess and dont clean up after themselves. The lock on my door when I moved in was kind of old and dainty so my brother bought new locks and kept a key and gave me one. A few weeks later I lost my key, So for the past week I askes my brother and gis girlfriend when you leave please leave this door unlocked untill I get a new key made or find my old one. I have a newborn, a 6 year old and an 8 year old. I am so busy I have not had time to get a key made yet nor did I find my old one. So, back to the begining I walk up to the door. My friend left because she was running late for work, I go to open the door and its freaking locked! (This is the 3rd time mind you, they have locked me out when I had the baby!) I am immediately enraged, Then the baby starts screaming. Hes covered in his car seat but the wind blowing was still getting in and I kinda heard it take his breath away. I have no one to come get me, I dont know anyone by where I live, my car is not here it's getting fixed, So I'm standing outside with a screaming cold and hungry infant, I call my mom and brother and neither of them act like they give a shit, saying"You shouldn't have lost your key." No I shouldnt have but right now thats not the point. I am so frustrated at this point, the baby is crying louder now. My 6 year old is getting off the bus anytime now, I tried every possible way to break in my own house, My brother dont get off work for about 4 more hrs, His gf dont have a job or car or anything and is always out with different friends, god only knows where she is at this point, So I set the baby down off the porch, I go to my yard and grab a brick and break through my window. I got into the house, with both of the kids. The baby is fed and warm, But now I have a broken window on my door, and I'm feeling stupid, and my family is telling me I'm stupid, but if I didnt break the window, Id still be sitting out in the cold with a screaming baby and a 6 year old. What would you have done? Did I overreact?