I feel neglected by my partner. What should I do? (details inside)

I feel distant from my partner because I feel like he’s too busy to spend time with me. He noticed that I’ve been more quiet and distant this week. He wants to have lunch with me tomorrow because he has a half day of work, which is thoughtful.
However, I feel disappointed in his usual lack of attention. I feel like a side dish to his full plate of life. Now that he wants to treat me I just don’t feel up to it because of my disappointment. I also feel like our relationship is mostly on his terms and he spends time with me when it’s convenient for him rather than making sure I’m a priority. He tells me that I am the biggest thing in his life but I feel like the smallest. I feel resentment. He’s coming home from work soon and I don’t want to really be in the same room today.
How do you think I should handle my feeling of being let down and neglected by my very busy boyfriend? I don’t see this cycle really changing much because of his job. Thanks.