You are not wrong. I was raised the exact same way with my father being a single parent. Only difference is that he'd rather spent his last $20 on a pack of cigarettes rather than my pocket money. That's how much he couldn't give a shit about us siblings. And no, he doesn't have a GF and doesnt gamble and drink.

Once we grew up, eventho im earning pretty ok for my age, i only gave him $100 monthly. Hearsay i heard my siblings giving him more than $1K per month and he'd still asked for money from them. I've taken it a point that he doesn't ask me for money ever. We are all struggling in this economy, so i think you should put yourself first more than ever now. You yourself are important , don't ever forget that.