I never thought of it as Logan himself didn't feel he deserved love, but the way you said it actually makes that make a lot of sense! everything he does is to push others away, so he doesn't get hurt himself, but also so he doesn't hurt them. maybe Serena cheating made him feel unworthy of love and also angry at others who get it? like a double-edged sword where he wanted it but couldn't stand the idea and the potential betrayal that could happen after the last time, so in response he shuts himself away and shuts any pathway to his heart, but well, where there's a will there's a way lol.