I agree with the previous responses.
I am someone who doesn`t want the people I am dating, to treat or feel about me, equal to their spouse.
However, it has nothing to do with depression or self-worth. Or fear of kids, etc. As TP suggested, make sure being secondary, isn`t because he feels second rate.
Be careful of the 'I want' fantasy as nycindie suggested, but also be careful of giving more then you receive. Sometimes relationships are lop-sided, but in that case, I would be uncomfortable receiving more then I could give.
Maybe that is a good way to approach your boyfriend ? Ask him about his feelings regarding the way love is given and received. Ask him if he feels there are ways he would like to express more to you, or give more, or anything he wants to work towards of his own accord.
Basically give him the opportunity to set forth his own ideas, rather then directing them to specific avenues. He might be one to express himself in unconventional ways, at which point you need to decide if those ways make you feel truly loved the way you desire.