rights of single mother - ex partner is a drug user

hello... just wanted to know what my rights are as a single mother, i have seperated form my ex partner of 10yrs, we have two boys together 6 and 3. i don't want to stop him from seeing the boys, but i would like to limit it... can i do this? he is a drug user on a regular basis, does this factor in? please help me...what are my steps from here?

[AFFA]

I wish to inform you that court considers the best interest of child. As a single mother you can claim child support from the father. If the father wishes to have visitation rights then he first will have to establish his paternity. In court when the father demands visitation rights then you can object on the ground that the father is a drug user and this may cast a negative influence on your children. You can demand that father's visitation should be to the minimum. In this you will have to show that father after taking drugs may either cause harm or may not take care of the child. Lastly, consuming drugs by a parent is often a point which is taken into consideration by court before deciding visitation rights.

AFF