He hasn’t texted me for a couple of weeks now. I always send him messages, asking what’s the matter and all but I didn’t get any response from him. We are in a long distance relationship. I met him online and we haven’t seen each other in person.
Should I ASSUME that it’s over or just wait for his response?
It's entirely possible that something has come up in their life, and they're having a hard time contacting you. Have you seen them active somewhere else, when they could have been talking to you?
I'm no stranger to long distance relationships. Constant contact can be hard to maintain when life gets in the way. So it's best not to jump to assumptions too fast... That being said
If it's been weeks, it's completely reasonable to start assuming things. Send them some sort of contact that's hard for them to ignore, and tell them how you feel. Tell them where you stand. Tell them you're worried, and that it's hard to hang on like this. Don't expect the worst, but be ready for it. Set yourself a pillow so that in the case that you do fall, it's cushioned.
Best of luck to you in all this. I'll keep my fingers crossed that things work out best for you
It doesn't sound like he's being very considerate of your feelings. Even with wanting to end a relationship, you should be kind and TELL your partner, how you feel, and why you feel that way. I dunno what is best, but I would personally assume it to be over. You deserve better.
Like @globox said, he could be unable to reply, otherwise if you know he is actually choosing to not reply, I think you can send him a message stating how you can't go on like this, you are there when he wants to explain what is going on but from now on you are considering you two on a pause. Then you act like you are on a pause, and try to move on. Good luck.