589 credit score-NEED mortgage/loan

I had to move out of state to Maine in order to find a job and my wife and I have been seperated because of this. She is stuck in Florida with our first baby on the way. We own 10 acres in Maine which I have been living in an rv on. In order to get my wife up here, I need to make our land livable. I need to get a loan or mortgage to do the following... driveway installed, well, septic, power and to buy a new or used mobile. $35,000-$50,000 will get all of this done. We owe nothing on the 10 acres.
I have been at my current job since May of 2010 and I make $3500-$3900 a month. I have 2 payments, a truck loan ($345) and a credit card with a $1,000 limit ($20 mo).  As soon as I can get a livable place for 2 people and a baby, I can finally be with my wife again. I cant stand the thought of my baby growing up without me while I wait. I have been working on my credit score for almost 2 years to no avail. My biggest issue is not having enough revolving accounts. Well, I cant open any accounts because of my credit! Its a catch 22 and I can't get out of it. Any help is MUCH MUCH appreciated. Even if I can get a loan to get everything but the mobile, we could live in the RV if we had power, well and septic at least.