I don't get it

I don't get it every time I turn around to pursue and make things right in my life I always seem to get smacked down in some way.  I just really dont know what to do I mean I have a certain plan I want to go to school and get better income and a house but that's going to have to come with time.  Other thing is I have always wanted a family and a girl to come home to ever since i was about 16 which is sad because of how young that is.  But here I am with an amazing girl who has two kids you think that would be the thing to make me a little on edge or worrisome but it doesn't i love these kids they are awesome.  The issue is the baby daddy of one of the kids stepping in to try again and again sigh it feels like a battle I cannot win  I don't wanna give up because I know where I stand I'm the only guy besides him she actually started planning a future with and she's put her foot down about her just dropping me for him because I'm not just the place holder.  But every day things seem to be pushing me out of the equation sigh it feels like its just going to be another situation I put effort into and failed. Sorry needed to rant its been eating me up and ripping my dreams apart.