I think some of the responses are a little harsh on this thread, but only because "I'm practically a single mum" is often over used very flippantly by people who have no ideas of the reality of lone parenting (financial burden, mental load, housework, homework, reading, bathtimes, lack of social life, inability to do very simple things like pop to the shop or go for a jog or have a wee by yourself)
My DC see their dad maybe 3 or 4 times a year (his choice) and have no financial support from him. I know some who have no contact at all with the other parent. This is a different experience to those who are co-parenting with an ex, and now find themselves less tired with more free time a few nights a week.
If you will both be contributing financially to things like food, uniform, childcare costs, new shoes, hobbies etc. and you will be sharing custody this will probably give you more free time and make you feel less tired than your current situation. In your case, you are already the only income and you have no social life, so perhaps it is more of a true statement than a knee jerk reaction to an inconsiderate partner.
OP, I understand that you haven't intended any offence to single parents. Good luck to you, whatever you decide to do, but do consider whether you will be a lone parent or a co-parent, as the two will be very different experiences and may or may not improve your current lot in life.