When EB and I were dating, we lived hundreds of miles apart. I work from home, virtually, and he commutes to his work and works in an office. Now, since I was "at home" I was moreso like you, and as things popped into my head I'd share with him via a text or email and then wait for his reply with anticipation. Yes, I liked the guy and enjoyed hearing from him! BUT he was not in the same situation I was, and I tend to be a more verbose writer and talker, and he is a quieter person and more selective with his words.
Soooo...I can identify with what you're feeling. You like the guy and recognize that he's a good person, but since he doesn't reply to your texts right away, you think he doesn't see you as someone who's "As Important" as those he does drop everything to reply to.
--this isn't about him at all. It's about you. Partially it's about trusting him, that he really DOES like you and think of you as important. Partially it's about thinking of yourself as important. Partially it's about seeing and recognizing the ways he DOES act like you are important to him. And partially it's about being transparent with him as you struggle with the previous three.
The reason I say it's not about him is because not everyone is a texter. Not everyone is an emailer. Not everyone is a phone caller. Not everyone is a writer. Not everyone is a talker! Part of the joy of getting to know him is learning the ways in which he ACTS to show you that you are important to him...HIS WAY, not your way. So if you see him speaking to you courteously, including you on future events, asking you for your opinion, and "making the effort" to be kind and thoughtful and loving in a myriad of other ways, then his actions are telling you he cares. TRUST his actions. The people he "drops everything to text back to" might be work emergency folks or might be people whom he thinks are so *****y he has to interrupt himself just to shut them up! Thus, to him, dropping everything to text may not be an action of love (at all!).
I won't go into thinking of yourself as important. I know that you know you are. You know that you know you are. Now all you have to do is when you feel "less important" tell that voice to be quiet and it's not true. I personally say it out loud ot myself so I think it and my ears hear it too. YOU are just as important or MORE IMPORTANT than anyone he texts right back to. He may LOVE the fact that he has the freedom to respond when he is ready and you don't pressure him! Wouldn't that be ironic?
I'll dive a little into seeing and recognizing what he does do to show you that you're important to him, because often we ladies will want a, b, c to show us we're valuable, and we're so fixated on a, b, c that we don't see that he's doing j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z! So one part I would gently recommend is to think of his actions--what he does and how he does it--and specifically look for all the little ways his actions say "You mean something to me." Look for little stuff and big stuff. Then, recognize that it may not be the way you do it, but those actions are the way HE does it. Now, note to self: it is smart at some point to talk about love languages and all that, but it's also smart to see the way someone is expressing their love and at least receiving the love that is being offered. EXAMPLE: My beloved hubby would call me as he drove into work and as he drove home--45 glorious minutes dedicated to me each way--and yet while he's at work, he didn't call or text. And it wasn't because I was not important to him! It was because he focuses on work at work...and he expresses value by never missing a call on the drive in and the drive home. Get it?
Finally, being transparent is letting your new guy see the Real You. When EB and I began dating, I was a widow and he was newly-ish divorced and frankly, we both had some issues--we're not perfect and we used to call it "landmines" where we didn't mean to, but on the occasion we'd accidentally step on the other's emotional landmine. But I don't think we would have gotten through it if we weren't transparent with each other. Thus, I do think it would be reasonable to talk to the guy and tell him openly what you've thought and felt, but also let him know you are working on seeing what he does do to show you he cares, AND maybe make a request. I love requests, because a request means they are free to say 'yes' or 'no' but they are told what the issue is and how to make it better! My guess would be that he may have some sense that something is bothering you, but may have no idea what it is or how to fix it. Thus, a request would be like a relief. IIWY I'd make a request along the line of "I am going to only text during your daddy-daughter week if it's pretty urgent, and I would request that if I keep it to urgent, that you would acknowledge the text within 1 hour" (whatever your details). That way, he knows that YOU are working on YOU and taking personal responsibility for your own self and feelings, but you are also making a request of him that would make life a little better for you. I like making requests by very literally saying, "May I make a request? Would you be willing to ____?" because it's me speaking up for what I'd like, but also asking them if they are willing to do it.