Back to work 3 weeks postpartum

I'm literally crying as I'm typing this. Im going to have to return to work next week.. only 3 weeks after having my son. I'm a FTM and wanted to take at least six weeks off but financially, I can not afford to do so. I have enough money to get through this month which means if I wait my 6 weeks, I'll be returning to work when I am completely broke.

My boyfriend just got sent to prison and this is the first child for both of us. Leaving my son so soon to return to work is the hardest thing I've had to do and I can't stop crying. I know that this is the best decision for me as a provider.

I take care of me and my son by myself. On top of that, I send my boyfriend money in prison and have to put minutes on my phone to talk to him. When I got pregnant, I was so sick that I couldn't work or do anything for myself. He paid the bills and made sure I had everything I wanted while I did nothing but throw up all day. Now that he is gone, I am going to make sure he is okay just like he did for me when I was down.

I just want some encouraging words or advice on how to deal with such a major decision.