No spark (long post)

I've been with my boyfriend for 19 months now. We never had a much of a sparky date life at the beginning of the relationship we were both 20 he was still at college (UK) I lived with my dad and didn't have a job or did anything. He would come see me everyday after college before he had to go home(he lived with his grandparents). We would go to the lake near were we lived about 3 time then stopped as it was in the winter we would just stay at mine on his days of and just watch TV or sex. 4 months into relationship we become pregnant anno we should of been more careful. Once our son was born we moved in together at a new home he got a job to pay bills and for us to survive on and I stayed home with our son 7 months past and we havnt had time to ourselves we havnt been on dates or even have the spark in the relationship we just jumped to the family part and the distants between us I feel like the relationship we have is a one we have to put up with each other. We always argue he has been sleeping on the sofa for 2 months now as he thinks it's easier we have little to no sex life now. I love him to bits he says he loves me he is planning to propose to me once he gets the ring sized right. He just says we don't have time for dates or to do stuff together coz of work or the baby and to run the house. Anyone been is this before I don't know what to do