Should I feel embarrassed

I'm split up from my child's "dad" now nearly 3 years he was never there for me or my son cared more about other girls and his drugs so I finally took enough and walked out it killed me to do so but I knew I wanted better for my son he gave me money for my son for 7 months then stopped said he lost one of his jobs and could afford it he only sees my son when it suits him but his parents see my son every week without fail. He told me couple months ago he will try give me money for my son every month but has never turned up with it I never have asked him for the money either but my sons birthday is coming up in 2 months time and I'm finding it hard with money so I got the guts to ask him and he more less told me no I feel angry but embarrassed aswell that I even asked him. Should I feel embarrassed or what do you think because I don't know anymore what to do 🙈😕