Is it normal that i haven't heard from my bf in 5 days?

I would like to know from you if you think this is normal and why this could be happening?

My boyfriend of 7 months has not contacted me or replied to my messages in 5 days. I was overseas for a month and came back home a week ago. Everything was great. We texted every day, not constantly but a few times a day, and he called me every or every other day when he would go to bed at night. Two days before I came back home, he left for overseas, on a three month trip. He is travelling with a friend. He had previously told (days before he left) me that he was feeling anxious about leaving and about not seeing me for another 3 months. I reassured him everything would be fine.

What happened when he left and I got back home, his messages were fewer and he hadn't called me once. I felt depressed from having come back from holidays and coming back to reality, and on top of that felt neglected by him, which in the past he had never done. He had always been a sweet, thoughtful and caring guy.

Last time I heard from him, we were texting, but my responses were a bit cold towards him, simply because I was feeling neglected by him. I then hadn't heard from him for the next 2days. I overreacted, and blocked him on watsapp. He did not try contacting me on Facebook or otherwise. A day later, I unblocked him and messaged him. just a "hey". Two days later and he still hasn't responded. I am guttered.

I also messaged him on Facebook asking if everything was ok. No response. He is not very active on Facebook, but two days ago he did comment on his wall, so he is alive. And he does have Internet connection.

What do you think is happening?

I have messaged him again just before on Facebook asking him to let me know what he has decided.

This is so unlike him, I cannot believe this is happening.

Any advice would be greatly appreciated.

I am so angry right now and tempted to block him on all social media so he cannot contact me.if he wants to end the relationship I want to move on asap. However, I would prefer to hear from him that that is what he has decided.

How long should I wait for his response before assuming that he no longer wants anything to do with me?

UPDATE

He just messaged me and apologised for not contacting me earlier. His sim apparently "hasn't been working" and he now has a new sim.

WTF

5 days with no contact???????

I am so upset