Sharing Our Innermost Thoughts

I want some advices please,
What to do if a relationship becomes obsolete?
(Please excuse for my bad english, i don’t speak it)

So me and my boyfriend been together for 2 almost 3 years. Our love was like a dream for 1 year.
Then the things suddently changed.
For now it’s so bad…
We spend more time together now it’s like we meet almost every day, but it’s not that good than it used to be.
I don’t want to make this story so long, so our love survived so many things.
One i was in a party with my best friend and a guy was tried hitting on me but i told him i am in a happy relationship but he did not seemd to care he kissed me. I immediately run to home and told him while i cried. He had the nerve to tell me i cheated. Then he forgived… Not to talk about how he never let me to see his phone even tho in a party he literally give his phone to his colleague girls to take pictures…
However we argue almost like every day… Sometimes he thought it was ok to hit me… I told him if he do this one more time i leave, and now he stopped doing it.
Last week we argued he packed my things and told me to leave forever. I was like ok, then halfway he called me and he was begging me to go home to him. I did because i love him to death.
We’re okay now and i thought about if we didnt argue this relationship is still toxic because there is no passion. There is nothing to fight for. I am still madly in love with him but i feel like he doesn’t. He just clings to me. Even in bed there is no passion and we don’t do it often…
I am still hoping i could save this relationship because i love him so much i would literally die for him.
I just don’t know why he fell out of love or if he still do loves me why does not he show it to me? Because he was not like that before.
So i would like to ask for a little help, how could i save this?