Spankings?

Let me start off by saying I am no expert on child psychology. What I am is a mother, and a child who was brought up with spankings as a form of punishment. I hated it and still do. I use to always think as a child this is something I never want to do, but also as a teen, after my mother died, that this is something I could never blame my parents for doing. I'm living my heart ache as a mom in an extreme financially distressed situation with my siblings and father as my primary other childcare aid and they believe in spankings.
I keep promising myself one day I'll be financially stable on my own with my son and I will never spank him again. For me as a parent it is just something I don't want to do. I get criticized and belittled by my family for my choice and feelings. I feel this pressure that if I don't agree and go along with them, given my current none existent financial freedom, that they would be unwilling to provide the childcare I need while I am at my college classes. Frankly I can't afford to be without them.
I spend my days puzzling about how I'll explain to my child when I can raise him solely on my terms about the discrepancy of our lives, from what we experience now. I won't and can't express to him that I was in a situation that by necessity to keep shelter over our heads I acquiesced to things against my core. I just want to get from day to day with him and pray that soon through hard work and education I can free us of some of the pains. I love my brothers and my dad, and I except that pretty much however I try and word this I'm going to hurt them. Truthfully I do care and I don't want that. I just want to do what will make me and I feel ultimately my child happy. I don' want to use spankings as discipline.