First of all you should be in right frame of mind. Do not blame yourself for being a single parent. Take care of yourself so that you can take care of your kids.
Obviously you love your kids but sometimes you are not expressing to them properly. This may take your kid to isolation as they are not old enough to interpret your kind gestures. Put an end to this one-way communication. Show them how much you love them and tell them how much they are important for you.
Being a single parent does not mean that you have no connections with outer world. Arrange family gatherings, invite other parents to your home or join a single parent group as this will help your kid to make their place in the society.
Follow a proper routine, plan their meal timings, play time, bedtimes as it will bring them under a schedule and ultimately they will be able to plan their lives.
Bring them under some rule and regulations but not as in military training school rather explain house rules politely. Ask them to help you in different kind of works like clearing the floor from their toys, books etc.
If your single parenting is the result of divorce or separation, do not refer your ex-spouse in negative way as it will leave a strong impact on your kid’s psyche and he/she will not be able to trust anyone easily.
Find a responsible and loving mentor for them. It can be anyone like their grandparents or uncles etc. Organise their meetings frequently as it is very important for your child to develop a trusted relationship also with some other person.
If you think that you are not doing justice to your child, no matter the reason, go for a quality child care. This will not only release the pressure on you but also help your kid to interact with outer world.