I second what others have said about accepting yourself and forgiving yourself. I try to remember that eating healthy isn't a punishment, it's something loving you do for yourself because you want to take care of your body.
I also think it might be good for you to talk to your boyfriend about your feelings of guilt and shame around food. I have different issues, but talking to my boyfriend about it really helps. I am trying to avoid sugar and eat enough protein to avoid blood sugar crashes. But I mess up sometimes, and I get so mad at myself for it. Having him know what I'm struggling with is helpful, because I can talk to him and say "I am so embarrassed. I am frustrated with myself."
And he reassures me and helps me stop that self-defeating, critical self-talk in its tracks.
Best of luck to you, and congrats on all the healthy changes you have made in your life so far!!! There is lots to be proud of at 170! You are 50 pounds lighter than you were at your heaviest! That is something to be really proud of!
One last thing: I have to exercise to regulate my appetite/thinking about food. The more I exercise, the less I think about food. Not sure if it works that way for everyone, but it certainly works for me and maybe it would for you too.