My girlfriend [26F] wants me [34M] to accompany her to Colombia for dental work, but I don't want to go. How should I handle this?

TL;DR: I don't want to accompany my girlfriend to Colombia, and I'm struggling with whether I'm being unfair to her.

My girlfriend (26F) and I (34M) have been together for two years and currently live together for over a year. She is planning to travel to Medellín, Colombia, for elective dental work to get veneers. She originally wanted me to accompany her, but I've decided that I don't want to go. We've discussed it and she has accepted my decision and is willing to go without me.

What I'm struggling with isn't really whether she can go without me. It's whether my decision not to accompany her is reasonable given our relationship, and whether I'm letting resentment influence a decision that I might otherwise make differently.

About eight months into our relationship, I accompanied her to Turkey for a nose job. International travel is very stressful for me, and I had a difficult time with the trip, but I went because the procedure was invasive and I knew she would need someone to look after her while she recovered. The experience ultimately brought us closer together, and I'm very glad I went.

This situation feels different to me.

For the past year, I have financially supported her while she was looking for work. She now has a job, but she still doesn't contribute toward rent or most household expenses because she wants me to be the provider in the relationship. I also generally take on more of the household responsibilities and planning, including cooking and cleaning.

I've increasingly become resentful about this dynamic. I feel like I'm carrying more of the financial and practical responsibility in the relationship, and I don't feel like we're functioning as equal partners.

There are also some issues surrounding her work that have affected how I feel about the relationship.

She does massage work and promotes herself online. Much of the content she posts is highly sexualized. I've told her that I'm uncomfortable with it and that it affects how I feel about our relationship. Her response has essentially been that I should stop looking at the content because she needs it for her business.

I don't want to control what she does for work. I understand that she has the right to decide how she conducts her business, even if I'm uncomfortable with it. At the same time, I feel that I'm allowed to decide what I'm comfortable with in a relationship. What has bothered me particularly is feeling that my concerns are being dismissed rather than discussed.

There have also been trust issues because she hasn't always been truthful with me about aspects of her work, and I've had to find out some things myself. That has made it harder for me to feel secure in the relationship.

These issues have changed how I feel about making sacrifices for the relationship.

With the Colombia trip, she has been expecting me to come and take on much of the practical responsibility: organizing the trip and itinerary, flights, transportation, navigating the country, coordinating around her appointments, finances, etc. She doesn't have credit cards, so she has also been relying on mine. She has offered to pay for half of my flight and the hotel, so I don't want to portray this as her expecting me to pay for the entire trip.

But I simply don't want to go.

International travel is stressful for me, and I don't want to take on all of the logistics and responsibility associated with the trip. And, if I'm being honest with myself, the state of our relationship makes me much less willing to push myself through that discomfort than I was before.

I don't think this is really about Colombia being unsafe. I spoke with someone I work with who lives in Colombia and previously lived in Medellín, and he was very positive about the city. I'm also not trying to prevent my girlfriend from going. She has made it clear that she is willing to go without me.

I'm willing to help her plan the trip, make sure she knows what to expect, and even give her a couple of my prepaid credit cards as a backup. I want her to be safe and successful with her procedure. I just don't want to be the person accompanying her.

And this is where I'm conflicted.

Part of me thinks that when you're in a relationship, you sometimes have to do things that aren't comfortable. I went with her to Turkey despite my anxiety about international travel, and it was ultimately a great experience for us. I wonder whether refusing to go now means I'm failing to support my partner because I'm allowing my resentment to dictate my behavior.

But another part of me thinks that there is a difference between making a healthy sacrifice for your partner and continually taking on responsibilities that you don't actually want because that's become the expectation in the relationship.

I'm also aware that I may be rationalizing my decision because I'm unhappy with the relationship. That's what I genuinely can't figure out.

How would you approach this if you were in my position?

Would you consider declining the trip a reasonable boundary given the current state of the relationship, particularly since she is an adult who is willing to go without me and I'm still offering other forms of support?

Or would you see this as a situation where I should put my feelings about the relationship aside and accompany my partner because this is the kind of sacrifice you make for someone you love?

More broadly, how do you distinguish between reasonably standing up for your own needs in a relationship and allowing resentment to make you withdraw from your partner?

I'm genuinely looking for perspectives from people who have experienced something similar. I don't want to simply be told that my girlfriend is wrong or that I'm right. I'm trying to understand what a healthy response to this situation would look like.