Should I get a lawyer instead of my public defender? (LONG)?

Long story short,I got scammed for $3800 by receiving fake money orders in the mail & cashing them.I didn't know they were fake,& the bank prosecuted instead of letting me pay it back.This was1 bank,but I went to 2 branches so I got arrested in 2 towns.I got 1 charge of larceny 4th (misdemeanor) in 1 town and was told by the public defender it was best to plead guilty so the other court would take the case.So I did thinking he was telling me what was best for me. I went to court at the other court yesterday & my PD there started yelling at me why did I plead guilty & why did the a*holes transfer it to that court?This second court I got more charges. One larceny 4th and 4 forgery 2nd's. The PD is not worried about the forgery's though he is worried about the larcenies saying the judge hates larceny.They offered 18 months in jail and I HAVE NO RECORD! Am I better off getting a lawyer? Will it not make go to jail? I have two kids, one is autistic and the other is 6 months, I cant leave!!