Falling in love is when you get an obsession about another person. But you can’t maintain an obsession like this for ever, and most people evolve that love into a deeper, more intimate, relationship.
The only difference between that and the love that you have for others (such as your parents, children or close friends) is that it is just that more intimate, since you don’t share quite as much of your life with them. Apart from that there is no difference. You don’t expect your life with others to be idyllic, so why with your partner.