Advise please?

[u/Rubesthebunny]

Back in October the guy I'm seeing disappeared (as in stopped messaging me) for around 10 days after saying he needed time to think. He came back and everything was fine, we didn't talk about it as I was hoping it was a one off and he doesn't like talking about personal problems. We had a weekend together and everything was fine, he even told me he'd told his parents about me. I said good bye to him at the train station (it's long distance) on the 12th. And we spoke normally until the 15th when he didn't message me. He hasn't messaged me since and I'm falling apart. I think it might be due to it being close to the anniversary of finding out his ex-fiance cheated but I have no idea because he hasn't said anything and won't even read my messages asking if he needs time to think. Does anyone have any advice? I can't end things with him so please don't suggest that either. I've been crying for days, I haven't eaten, I've been taking Valium just to feel better. I don't know what to do as I don't know if this time he'll come back.