I concur. As Roxy was his first genuine girlfriend, I believe he felt a little insecure about their relationship and constantly feared losing her. His desire to stick near to Roxy was a factor in his decision to join the Providence. Also, he feared that Roxy would find another shoulder to weep on and stop needing him if he left. However, Roxy and Steve both had dynamic personalities. Over time, they both grew up and eventually went their separate ways without ever losing touch.
I definitely think Steve threw his life away for Roxy , all his decisions were made in the hopes of winning her or keeping her. Even when she had a boyfriend or when she cheated on him, he was still trying to win her back! I believe he was blindly in love with her, so much that he did this all to himself, and still Roxy wasn't satisfied.
I think the time he spent trying to please Roxy could have been used to get into law school. She was at the forefront of every decision he made. However, his decision to join the police paid off.