Miscarriage thoughts

My So and I are having a hard time financially and just found out I'm pregnant again after my IUD and plan b failed. The other times we used a back up of a condom except that once. 
I'm so nervous and scared to have this baby, I'm just having a hard time thinking things will be okay especially when we already have a baby that's 16 months. 
As much as I hate to say it I sorta wish I would just have a miscarriage.  I fell like a monster for even thinking it but it's the truth. 
I'm just so lost and unsure right now.... 
And please don't be rude, I don't need to hear your opinions about how horrible I am.