I’ve been friends with someone for a long while. We've taken a few trips together over the years.
I feel like we've drifted apart, although I may be the only one that feels this as I actually think they've ceased caring about much at all to do with me. Their attitude towards me is such that it reminds me of a yo-yo... one day they'll be the person I have grown accustomed to and can talk to for hours and comfortably spend time with, and the next they'll be someone who ignores my messages, stares at their phone during meals together and makes no attempt to socialise with me past the bare minimum. Even our conversations over instant messaging have drastically diminished. Furthermore, whilst some shared interests remain, others have steadily drifted apart, even down to something as inconsequential as music tastes. I will often try to indulge them in new interests, but the same courtesy isn't quite afforded to me so I prefer not to discuss my interests with them after one or two times, as a general rule of thumb.
Essentially, whilst I dedicate considerable time thinking about this friendship (truthfully my only close relationship, and theirs too, as far as I know), somewhat resentful that we don't socialise like we used to, and wondering about their well-being (is it personal struggles of some kind - i.e. depression? - that has so dramatically changed their personality or regard towards me?)... they don't seem to share the concern or make any move to act in any way that would redeem recent behaviour.
In short, I think it's time to move on, as I'm investing more in this friendship than they are and it's, I think, emotionally damaging to me. There are many many examples of situations and circumstances I could describe but the overall gist is that I feel taken for granted and underappreciated. I'm wasting my time trying to connect with someone who doesn't seem interested, but somehow, in certain capacities (like travelling together for a month to a foreign destination and leaving me to plan the trip that they suggested in its entirety!) they still expect some level of loyalty and consideration from me.
Cancelling the trip is not an option and I still very much want to go but I'm afraid of what attitude I might face during the trip. In our last trip together (a short holiday interstate), I felt that within a very short time, their attitude was that of someone who would rather be anywhere else. Petulant and reluctant, often expressing that they'd rather go back to the hotel than explore a new activity. It wasn't a pleasant experience and I'm somewhat fearful that the same might happen on this considerably larger trip.
How would I deal with this? If we find each other disagreeing on the day's activities, or if I want to do something but am getting the "vibe" from them that they would rather not - I don't want that to spoil my enjoyment or make me miss out on experiences that I could have, only because they have fallen into a sullen mood where they spend most of the time looking at their phone looking bored and disinterested in my company, let alone any scenery surrounding us. I'm unsure how to deal with this without causing hostility between us, which would be quite unfortunate when in a foreign country with nothing but ourselves for company!
I'm socially anxious as well, I've had situations in a previous recent small trip where they would refuse to do something as simple as take a photo at a landmark, either with me or even of me, and I lacked the confidence to feel comfortable using my selfie stick or to ask another person. These were isolated incidents, often in heavily crowded attractions (they're not a fan of crowds) but seeing as I never know what attitude to expect from them nowadays... that's a very likely scenario to happen. Personally, I have resigned myself to knowing that I have to build up the courage to get the outcomes I desire in these situations, but I don't want to do it in a way in which my frustration or unhappiness will be apparent to them, so as to not create animosity.
Basically I feel like I’m between a rock and a hard place. I want to enjoy my trip but am going to be travelling with someone I don't feel I can necessarily rely on or draw any enjoyment from - in fact, there's the possibility they could taint certain aspects of it. How do I navigate this diplomatically so as to step on no toes, or the least amount of toes? I want to look forward to this trip but the uncertainty of our relationship is causing me anxiety instead.
Suggested TL;DR
How would I negotiate the situation when my long-term friend is acting sullen and uninterested in our activities or is exhibiting an attitude that is sullying the mood? I don't want to miss out on opportunities or experiences but also don't want to antagonise them or create an even more uncomfortable situation...