EEA national claiming benefits, 20 years in UK

I am an EU national (Polish) but I believe that I am not entitled to apply for permanent residence on EEA route as I have been claiming social funds (housing benefit, tax credits) for the last 7 1/2 years.
I have been in the UK since November 1994, first on student visas, then from 2001 I think self-employed, and from 2005 working as on basis of Poland being in EU. I was away from the UK for 9 months to give birth to my child from July 2006 to March 2007. The father of my child is British but I haven't been in touch with him since January 2006. I need to get Indefinite Leave to Remain as there is nothing for me in Poland after 20 years in UK. Could you please advise me on my options.
Thank you