Is my (19m) boyfriend overreacting and being selfish?

I (18f) have been in a relationship with my boyfriend (19m) on and off for a good three years now, recently we have made a break through and managed to have a stable relationship without having to breakup and get back together.
Background info = we are long distance but manage to see each other at least once every month and a half

So yesterday I was talking to my mom about my cat who’s very sick and she said that we can’t afford to spend a fortune on her at the vet as she’s very old, which I agreed and then we both settled on getting her put down if she doesn’t make a recovery (recovery is unlikely as her problems seem to be coming from her mouth as she’s always drooling and she won’t let us touch her mouth so we think her teeth are rotting so there’s not much else to do but put her down)

I’m still very upset by this as I love my cat very much. I texted 3 people about this
My boyfriend
My best friend (18m) – Tommy
And my other best friend (17f) – amber

When I texted Tommy, who LOVES this cat, he was online on WhatsApp and then went offline and that had upset me a lot bc he knew how emotional I would be if my cat died and I felt like it was extremely rude to ignore me as well.

But amber came online and comforted me and then I started on a rant about how Tommy ignored me. As I did that my bf came online and I responded 2 minutes later to tell him I was also talking about my cat to amber so that’s why my responses are slow. And then he made the comment “ok just date amber then” which set me off because why would you make a comment like that when I’m obviously really upset.
I got mad and cussed him out and he said I’m being outrageous.

I went offline because I just needed time alone and when I came back we talked it out. But I told him that I feel controlled when he asks why I don’t reply him fast and that just causes me to stress out when I’m having a conversation with someone else and then he comes online because I know he’ll ask why I’m taking longer to reply and then I feel like I can’t have a conversation with another person without him questioning everything.

I tried to explain to him that I only ever talk to two people at once if I’m having an important conversation with someone else but other than that I always reply him first and I reply him faster. So I’m only ever feeling controlled when I explain to him that I’m talking to someone else and he’s still on my case about why I’m not replying him faster
His exact response was “you can talk to two people at once cant you”.

Eventually I told him that I feel like I lose feelings whenever I start feeling controlled. I also said that it’s the same effect when he communicates his feelings and I do what I can to make him feel better – acknowledging what he’s saying, trying to apologise for how he feelings and then reassuring him in whatever way I can to make him feel more secure. And every single time I do that he never even says thank you, he never replies or even acknowledges what I try do and that just makes me want to put distance because it’s like I’m being ignored and then he still complains about how he feels even though I try make him feel better. So I feel like I want to lose feelings because he still blames me even when I’m comforting him.

The reason why I brought this up was because last week he has told me when I go offline to take the space I need after a fight it will lead to him losing feelings because he likes to talk things out whereas I need time alone to calm down or else I’ll be too emotional to have a mature conversation.

Instead of asking what to do in situations where I feel controlled he ended up just saying “I love you sm and that’s why I want to always talk to you and so maybe since I’m smothering you it means I should back away and retract my feelings” which I felt was actually unfair because I had asked him to just give me some space when I tell him I’m texting someone else and honestly I feel like it’s a reasonable thing.

But at the same time I don’t know if what he’s doing is right or not. I feel like he’s overreacting and what he’s doing is going to be our downfall because I don’t need him to take a step back and remove the feelings he has for me, I just need him to be more understanding and patient. He said himself that he’s very hurt and feels numb and that he can’t be patient and thinks it’s best to just remove some feelings.

Honestly idk what to do.
Every other aspect in our relationship is fine. It’s just this one thing.

One more thing – amber is moving to the other side of the world in 5 days
And because of what Tommy has done and other things in our friendship I’ve been feeling like it’s one sided recently and that’s caused us to drift
So I’m losing 2 friends and I may be losing my cat within the next few days so my bf putting distance between us hurts more because now I’m losing 3 people and my cat.

TLDR –
My boyfriend said he’s taking a step back and will make himself lose feelings for me because I said I feel controlled when he constantly asks why I don’t text him when I’m online having conversations with other people. Recently I have been having friendship problems with one best friend, another best friend is moving to a whole different continent and my cat will most likely be put down and my boyfriend thinks that his decision to stop loving me as much is the best one instead of asking me what he should do to make me feel less controlled.