Why is my boyfriend acting different?

Everything's going great between me and my guy. But lately, I feel like he's acting different. Every night up until a month ago he'd text me something like 'goodnight beautiful, I love you' or good night sweetheart. Now he texts me goodnight and just says 'i love you xox'.

He doesn't call me any cute names now either.

When we text, if I tell him I miss him he won't say he misses me back he just sends a sad face.

If I talk about a celeb guy, he'll get mad at me and will ignore me, and he never used to act like that.

He swears a lot, and he never used to

He used to complain about how I didn't show my love to him enough so I've been showing it more. I thought I was doing pretty good until he told me tonight that I was being too clingy

I know these things aren't that big of a deal, but I'm just curious as to why he's acting different