why men are emotionally distant in a long term relationship??

Hey guys, i hope you all are doing good. I am not here to share my sad story and how miserable i feel about it. I just want to share a brief story.
I am in a relationship with my bf for almost 3.5 years. We broke up last year in august end and got back together after a month. Reasons of breakup were me being insecure and he was hiding stuff from me and lying to me. We both were frustrated so i broke up and followed nc and got him back after a month. That was the break up part.
We tried to adjust till december. The strange part is he was not interested in talking about the reason and problems between us. He always told me to be cool about everything. In the starting of our relationship, he was so romantic. Though we never go on dates but our talks were intense and he used to tell me how much he loves me and can do anything for me.

He still loves me with all his heart i can bet. Love is not the issue. But he doesn’t show it. Seems less interested in spending time with me and rarely says that he loves me. I know the bliss stage is gone but i am still the same so why cant he be?
He isn’t cheating or anything like that. But his behaviour sometimes disturb me. I dont want to have any talk with him as it will only create trouble. I am okay with the things foing but was just wondering why is that so?
He used to ask me to marry him in such a romantic way. Used to hold my hand and kiss me gently whenever he could. Now he just give me a kiss when he’s leaving.
Next month is my birthday, i asked him to come with me for iceskating. He simply said no take your friends, we will meet in the evening.
I am not sure if we will celebrate Valentine’s day (we never celebrated it). But part of me says that he will do something. Even would come to meet me. I dont know…
Any insight ti my story or in general?

He talks less and is emotionally unavailable and never talks about emotions nowadays: /

I know how you feel, that’s kind of how my ex acted before we broke up…it’s painful, I don’t like to think about it. How you feel is exactly how I felt for awhile. My relationship wasn’t very long term, but it was going to be. I was emotionally unstable for anything, but I was already depressed, and I had upset my best friend and that really tore me up, it makes sense to me. I wasn’t the silly girl he loved oh so very much anymore, I didn’t say weird crap to get him (or anyone) to smile or laugh. I just sulked around. Girl, I know you’re pain

@Confused girl
Sorry to hear about ur story but i am not in pain. I am disappointed to see a new him. And was just wondering the reason behind it.
I cannot do anything about it. I am just trying to give him his space and never become the clingy one. Though i reply to his text right away. I dont want to create any more trouble for us but just wanna know the reason behind him being emotionally distant!