Discontinuity in payment of Special Child maintenance

I am a single mother with a special child who is suffering from Multiple Disability and is non-verbal. I have filed a Child maintenance case in 2018 at the Barrackpore District Court for which only a very meagre amount of Rs 9000 was sanctioned as lesser salary was possibly shown before court by my child's father. It may be noted that I have asked maintenance only for my child who is disabled. He was giving the small amount of Rs 9000 but giving it with lot of discontinuity which is causing a lot of difficulty for me to cope up financially. I was doing a job long back which I am unable to continue as I need to look after my disabled child and carry out his therapy classes. I even had to cancel some of my child's therapy classes due to financial problems. I request the legal community to provide advice on whether this child maintenance amount can be increased atleast to Rs 20000 and ensure payment on a regular monthly basis for my disabled child's development.