How will i cope now? 4th baby!!?

I had my first daughter Alyssa at 18 and me and my fiance pulled together to give her the best life possible, but we were shocked to discover just after her 1st birthday that i was pregnant. I gave birth to my 2nd Ella just 6 months after finding out. i got on the strongest contraceptive pill going. it was all in a daze. i had a newborn and a 1 1/2 year old. i struggles though i must admit, my fiance worked to support us and i cared for the kids, until Alyssa was about 3 and i fell so ill i couldnt move, my mum and fiance cared for the kids, it took doctors 5 months to come to the conclusion i was pregnant, i suffered all the way through the pregnancy until i delivered Olivia 3 months later. i was so happy to be back to my normal self, only i had 3 daugters. all under 3. after 2 years My finace decided to have a vasectomy. now to my problem, 5 weeks after his vasectomy i am expecting again, i have 2 months left, how the hell will i cope, Alyssa is now 5, Ella 3 1/2 and Olivia 2. x