A dad has been working way too much for many years at the expense of time with his family, but now wants to change it.
Dad: Emily is growing up so fast. I've already missed out on a lot/too much. I don't want to miss out anymore/any longer.
1) Is 'miss(ed) out on' correct in this context?
2) How would you write the two sentences?
It depends on who Dad is, his level of education, his mood at the time, the way he normally talks, etc. All your choices work.