I'm a 26-year-old woman feeling overlooked and unsupported by my 28-year-old partner. Should I consider moving on?

My partner and I have been together for five years. About five months into our relationship, we moved in together and spent four years as roommates until he decided to move out to focus on his startup. I understood his decision, as I also hold a demanding leadership position, and we both want to advance our careers before considering marriage. He relocated just 15 minutes away, and for the first six months, we spent weekends together, as well as time during my periods. However, things began to shift when his work travel intensified. He has never been the best at texting, but during his trips, his responses became almost nonexistent, even after I expressed how much it upset me. I stayed up late for calls, but he always prioritized work instead. While he chats enthusiastically with friends, he barely acknowledges my messages, even when he's online. In person, he’s often glued to his phone or laptop; while he listens, it feels like he’s not fully present. I’ve conveyed my feelings about this, but there hasn’t been any change. For my birthday, I like to throw big parties (which I cover the costs for). Last year, when I requested his help with the guest list, he told me to handle it myself, despite the fact that I take care of his birthday plans every year without complaint. He hasn't given me a gift since our first year together, and he doesn't acknowledge our anniversary. I've come to expect minimal effort—perhaps just dinner. It’s not about money—he earns more than I do, and I’ve never anticipated financial support from him since I treat myself to what I want—but his lack of initiative is painful. Our intimate life has dwindled as well. I stopped trying to initiate after facing frequent rejection due to his low libido, even when we were living together. Now, I often feel sad after moments of intimacy. He rarely visits me, and when I go to his place, he sometimes calls me a distraction. Recently, after a light-hearted joke about him not opening the car door for me, he snapped at me to “get the f*** out of his house.” I still have feelings for him, but each meeting leaves me feeling heartbroken. He is kind, intelligent, and genuinely cares for me, always putting his work aside when I'm going through a tough time. However, I’m exhausted from asking for the bare minimum: flowers only when I request them, and dates only when I organize them. I don’t see the point in staying when I feel I receive so little in return. He claims these are just our growth years and insists things will improve after marriage, but I’m beginning to doubt that. He was so affectionate when we first started dating, and I can’t quite understand what has changed.