I can strongly relate to this, OP.
I was in a relationship with my ex for over a year. When we first met, he tried so hard to make me his gf and I eventually agreed.
He created his own business with a partner, and because my ex is an extreme workaholic and terrible at communicating, his business partner left him.
My ex and I used to go to beautiful places together and spent a lot of quality time. However, as soon as his business became successful, he had less time for me and "pushed" me to the corner.
He made no time for me and there were times where he will neglect me completely and not talk to me at all.
He would always say "I don't have time".
I even help him out with the work load to get some time together, but it just wasnt enough.
Everytime we have a conversation, he will talk about work and never about something else.
All the managers and family members told him that he needs time to relax and focus on other things.
He would work consistently and won't get back until the next day or 11pm latest.
After a while, I got fed up and eventually left him because it feels like he gave up on the relationship, doesn't care about me or willing to cut down on his obsessive workaholic life style. I couldn't take it anymore, he made me feel unhappy and on top of that, he was abusing my emotions and mentality.
Now, I've been focusing on myself and catching up on lost time. I feel like a heavy load has been lifted, and I feel free.
If you feel that nothing's going to change anytime soon, then you don't have to stay for the sake of having a relationship.
Talk to him first, and if it gets out of hand, there's nothing wrong with walking away.