I'm sorry to hear about your situation. It's a little scary for me to post this because I was in the same position 2 months ago, but I was in the shoes of your boyfriend.
Scotty girl got it spot on: it is absolutely how you spend your limited time together. If your boyfriend is serious about the relationship, your time together will be something you two can treasure, and that will keep you going.
My ex and I unfortunately didn't get there in the end, largely because there were issues that were simmering from my past which I didn't recognise until after. But I'd absolutely second the idea of going on a short holiday. My ex and I hadn't been on a holiday for a while, and that made it even harder to see past the daily grind. I really wish I'd just dragged her along on a holiday one weekend, instead of letting her work get in the way. And ditto for my own work and ego as well.
So, from someone who 2 months ago was standing where your boyfriend is currently standing, tell him how you feel and be firm about what you expect from him. 6.5 years is a long time and we can forget what we love about our partner but sometimes, it just takes a little spark to get things going again. If he's not willing to contribute to the relationship, then it's not worth being lonely and waiting for him to realise what he's missing out on.
The only other thing I would add is, and you're probably already doing this, don't forget to ask him if there's something bothering him which is making him pull away. I don't know what he's like, but I need a little bit of prompting to open up.
I hope that helps and let us know how you feel. This sounds very hard for you, especially since you still love him and are trying to make it work.