Am I an unfit mother?

I am a mother of 2 children a little boy 10 months and a 4 year old girl. I was recently divorced from their father and moved to a different city because I could not deal with his infidelity. The city I moved to so far this year I have held 4 jobs. I am not working due to the fact I could not afford to pay someone to keep them plus pick them up from daycare and school plus no emergency person to pick them up when they are sick he is only enforced to pay me $340 a month for our children. I was trying to explain to him when you have kids you have to upgrade to a bigger place its not like you can have a one bedroom with a boy and a girl. He wants to get his kids saying that I am not a good mother because I do not have a job. I do my best I made sure that I kept my appointment for foodstamps so they can eat and Medicaid to go to the doctor. The child support helps me out some. If his parents and my parents would help more things would be different. I am a certified pharmacy technician waiting on an opening. I have always supported my kids financially. It is June 9 and I have started school shopping almost finished with my daughters things. I bought my son clothes ralph lauren clothes from the store they were on sale. My ex has a criminal record just recently released from federal probation. I believe it is jealousy because I have a nice place and he wants to see me doing bad. Note everytime he sends child support it is spent on the kids and utilities not on me. I just bought myself some shoes its been 4 years because I put my children first. Does it seem as if I am unfit.