How do I 19F know if my long‑term relationship is fading or if this is a normal phase with 18M?

Throwaway because I don’t want this on my main.

l've been in a 4 year LDR that's had both good and bad times, but lately I feel like my boyfriend treats me more like a friend than a partner and rarely puts in effort. When I bring it up, he changes briefly, then falls back into the same pattern; spending most of his time on games or with friends, even when I visit, and leaving me feeling ignored and hurt.

Things have built up over time, especially after he removed signs of our relationship on Discord, which led to a big argument. Recently, he matched profile pictures with another girl, which I see as crossing a line. He apologizes and says he'll do better, but it never lasts, and I'm exhausted.

At this point, saying "I love you" doesn't feel the same, and I feel like l've already been grieving the relationship for months because of the lack of effort. Now I'm questioning whether this is just what happens after being together so long, or if it's a sign that it's time to let go.

TLDR: I’ve been in a 4 year LDR, but lately my boyfriend treats me more like a friend and puts in less effort. Even though he apologizes and briefly changes, he goes back to the same behavior, which leaves me feeling ignored and emotionally drained. A recent situation with another girl made things worse, and now I’m questioning whether I’m staying because I still love him or just because we’ve been together for so long.