I think you need to speak to your partner about this. It sounds like you two are both just stuck in a routine, and then with the awful news of your mc, that is bound to make you question things.
But it isn't fair on your partner for you to hang around feeling frustrated, say nothing, inevitably nothing changes and you leave. How old are you both (roughly?)
I think you should ask to sit down together and tell him that you are feeling really frustrated with how the relationship is at the moment. You feel like it has stagnated and you're genuinely worried. Routine is nice and well, but too much of it can lead to the death of a relationship.
He needs to know that this is important to you before he can decide whether or not he wants to change - and also bear in mind that once you have got used to doing the same thing over and over (local pub) doing something new can seem really unnecessary, boring and stupid at first. So don't be surprised if the first few times he says it is just a hassle. Try and stay positive, and discuss the things that you both liked about whatever it is you did.
Here are some examples of stuff you could suggest that you guys do:
A shared goal (for example, both run a half marathon, or 10km, or do a triathlon, or whatever)
I think anything like this - provided you can both "get into it" is really good, as you end up discussing your progress, comparing strategies, running together, etc. And the shared, tangible goal is not to be underestimated!
Go on holiday somewhere you wouldn't normally go
Every year we tend to go back packing around some part of the world which we have never been to, and it's always an experience that we talk about for years afterwards. Maybe backpacking isn't your thing, but consider a holiday that isn't just "turn up at hot destination. Go to resort. Stay on resort". Because with stuff like that, there is sod all excitement. It's just.....laying around. If you would prefer city breaks consider cheap flights to other parts of the EU. Croatia has some gorgeous places you can go hiking, kayaking, etc. Dublin is one of the friendliest places I've been to, and the pubs are amazing. etc.
The good thing about travelling in the EU is that you can easily go for a weekend as well.
Socialise together more
We socialise pretty regularly together, but not as much as we used to. It always surprises me how much I love seeing the other side to my partner when we are out with others. And you can also gossip together afterwards!
. If you don't have many mutual friends, there's no reason why you can't bring them together. Why not suggest a "dinner club" where every month, or fortnight, one person has to cook dinner for everyone. Then after dinner you can break open either a pack of cards or a board game (do NOT under estimate board games!!). I'd really recommend "Cards Against Humanity" if you don't have sensitive friends.