I started full time study when DS was about a year. I am doing a PhD and it really is a full time job. There is simply no way I could have done it on top of full time child caring. I have only been able to do it as DH has totally supported me the whole way. Even with that, it is still exhausting honestly as I still spend a lot of time with DS because I don't want either of us to miss out on the time we have now. I can't wait to finish. I know that in the end it will be worth it and that has kept me going. Don't want to put you off though as everyone has different experiences.