He felt like if he let go of her then he'd lose control of himself and everything else in the world. Things had been so wrong lately and the only thing that made much sense right now was her. She was all that he had left of Harry and he had to hold onto her as tightly as he could for fear of losing his best mate completely. "I don't know if I can do this. I don't know if I'm good enough to make it without him."
Ron wasn't incompetent, but he had always had Harry by his side and they'd always worked together. Now he just wasn't sure if he could go it alone. He had Hermione, but it wasn't exactly the same, seeing as he saw Hermione in a different way these days than he had before so their relationship wasn't like his and Harry's had been. Ron was what Harry would miss most in the world and while Hermione might be the love of Ron's life, Harry was probably the one that Ron would miss the most as well.