What do I do?

@ZestfulZalyn

Hey there, hopefully you are doing well. There's a few things I would like to point out;

I've been dating this guy for almost one year. And honestly I've never been happier. (I would really be careful with this because this is a sign that externally the relationship is making you feel happy, but perhaps you may not be doing things to feel happy without the relationship) He's always made me smile and laugh even when I've been down.

But recently, things haven't been so good lately. I feel like he doesn't care as much about me anymore. (Dont ignore this sign, its trying to tell you something) He stopped talking to me as much, (This is a sign he stopped investing in the relationship and slowly is backing away from you. There could be various reasons this is happening) and I have to be the one to start conversations. (I can tell you fear losing him and being abandoned, so the anxiety is making you want to close the distance between the two of you. This will make him feel smothered and trapped, and theres more investment from your side than his, so this will make him back away) He's also stopped caring about what he says to me. (Dont ignore this sign either. Something inside of you is trying to tell you something, but theres a chance you dont trust how you feel because of your upbringing) He's been more explosive and just recently we got in an argument. (This is a major red flag, its communicates to me that he is impulsive, lacks emotional self control and is sabotaging the relationship. His behavior will kill al safety in the relationship, and it will make you walk in eggshells) He yelled at me and said some unkind words. (This shouldn't be tolerated. He is coming across as abusive and unkind. He mistreated you here, and theres a high chance he will do this to you again) I didn't like how he treated me and I said maybe we should have a small break. (This tells me you are highly invested in him and don't want to be alone, so you are settling for a break than to walk away. The way people treat you is how they value you, and people will treat you in the way you view yourself. The more you tolerate this, the more he will do it) Right after I said that immediately regretted. Because I don't want to instantly have a break. I want to communicate with him. Tall about some problems we might have. (This is an indication you might have a hard time expressing how you feel and setting boundaries) Maybe he's been going through something. (You are making excuses for his behavior) But he immediately agreed to it. And I regret saying it so much. Because I really love him. And I know he loves me too, (Do you feel this is true after the way he treated you?) and we were planning on having a future and everything together. (I want you to really think hard about this. You didn't specify the exact amount of time you two have beeen together, but imagine yourself being with him after the things he did recently?. I promise you things will not go well because he is showing a lot of behavior that will hurt you and make you feel disconnected) But I feel like I make him doubt us. (No, his actions are making you doubt things because it didnt feel safe the way he treated you) I had a panic attack and it was hard to type (since it was texting). He calmed down and eventually I got a bit better. Then out of no where he left me since he was tired.

If he really loves me, wouldn't he have stayed up then? (I feel you might be having unreasonable expectations right here. I do feel he wasn't considerate, and should have arranged a time where you two can talk) Wouldn't he talk this through instead of giving up on me that quick? (You wanted the break, but the moment he didn't agree was when you felt you were about to lose him. I do feel he is quite toxic and he will get worst as time passes by) What can I do to make him happier? (I dont think you should be asking this question. The questions you should be asking yourself is "Its this person someone who is emotionally healthy to be in a relationship?" "Can he and I make a healthy relationship?, "Its his behavior going to get worst over the long run?", "If i marry him, how its going to be after the way he mistreated me?". You are more focused on making him feel happy, than paying attention how you feel) I feel like I also have a quick changing attitude or that maybe I'm the one overreacting. (I can tell that growing up people made you feel guilty for their behavior and actions, so now you internalize it as "Everything is my fault". I think he is the one that needs to change because through his actions he has proven to me that he is toxic and insecure)

I agree with @freshlight64 based on the information you provided.