He stopped saying it back

[Beth8]

I’ve been with my partner for 16 months and we live together. We have the usual ups and downs but recently I’ve found him harder and harder to read. 
He makes a lot of jokes at my expense and then calls me too sensitive when I call him out on it. He generally just seems volatile. 
But the thing that is bothering me most of all is that he doesn’t say he loves me anymore. In fact it’s been months since he said it. The last 2 times I told him I loved him he said “aw thanks”. 
I’m am questioning what this means for us. He still plans our future together and acts like he wants to be with me. Is it normal to fall out of love and still want to be in a relationship? Or should I get off the sinking ship before things get worse? 

[basil67]

He's pulling away.  But given his volatile and unkind behaviour, perhaps this is a good thing.  Do you really want the rest of your life to be with someone who puts you down?

[ExpatInItaly]

8 hours ago, Beth8 said:

But the thing that is bothering me most of all is that he doesn’t say he loves me anymore. In fact it’s been months since he said it. The last 2 times I told him I loved him he said “aw thanks”. 

If he used to say it but doesn't anymore, I think you already know that this is not a good sign. Add in the jokes at your expense even he knows they bother you, and you're seeing that you two are not actually a good match. 

8 hours ago, Beth8 said:

Is it normal to fall out of love and still want to be in a relationship?

There are a lot of people who will stay in relationships even when they're not that into the other person anymore, yes. Many stay out of a sense of security or complacency. It doesn't bode well if the other person is still there because they genuinely love and want to be with their partner, obviously. The other will nearly always wind up feeling like a roommate rather than a true romantic partner. 

This doesn't sound like a viable relationship anymore.