Feeling discouraged..

We arent having any luck getting pregnant , and i know its all because of me i havent had a child my self at all but my SO has a daughter with his ex and it makes me upset and sad and feeling lonely because we want one of our own but its not happening going over a year with nothing but false hopes is crushing debilitating almost especially when my siblings both had kids no problem and i can never seem to get things right :( rant over