Tired but still together

It will be 20 years together next year. We did break up 3x in those 20 years but never for more than 4 months. I always let him back. He did get verbally abusive in the past but that calmed with marriage therapy and just growing up. I am so confused. I do love him. Neither of us are fully happy but neither of us want to be apart. The more I do the less he does (and usually happier he is). Even after 19 years we keep falling apart. It's so frustrating. It's like the icky time he's willing to make an effort is if he thinks I'm too the point of wanting to leave. Of course he tries more but then his insecurities make him act controlling. I want out of this cycle without having to actually leave him because I'm content and secure. I really miss physically being with a healthy person, but remind myself I took him back, he's been obese the last decade and when I'm with him I usually am overweight too. It's tiring but I continue to make it work. I just don't want to get to 50 or 60 and feel like I wasted time.