cps child protective custody grandmother that can't have her grandchildren based on felony background 4 to 10 years old Houston, Texas

 i am a grandmother of 3 beautiful children that was taken from their parents because one was on pills and the other one was already in jail for assault on someone other than a family member. i was yes in jail for a drug possession that many times i asked for help and couldn't get until in 2007 i got def. adj probation for 4 years.  went to rehab. finished went to intensive out patient completed graduated court and got off of probation 1 year early recieved documentation on this and the cps case worker will not even talk to me, she said that because of my record whether i was able to turn my life around it did not matter i still could not have my grandchildren there is nobody else to help with these children and i will do anything and abide by any rules and regulations to get these children back into the family.  as i was in state jail in 2001 and 2002 i went to changes classes, parenting classes, and others i am now in college fixing to graduate with my associates degree in criminal justice going on for my bachelor's degree at university of Phoenix but does this matter to cps how i have changed and my own children are trying to help as well, they helped me attend all my meetings, took me to court appearences, but still cps does not care.