I do not think you are crazy and understand that you are trying to preserve something that is very important to you.
That said, I think that what you are trying to do for the advancement of your career is very important to you as well.
I understand that your relationship is serious...a serious and strong relationship can state the tests that come up against it. If your relationship is as strong as you believe, it can withstand something that is important such as a Fulbright.
I think...at this point, you should have a conversation with the person you are in a relationship...and speak to one another on a deeper level about how strong this relationship is and the kind of challenges that you are both willing to go through for the advancement of BOTH your lives.
This is a once in a lifetime opportunity and you already stated that the two of you were not dating when you applied. You stated that he is a bit older and would like to settle down. There is a responsibility that is taken on by someone who chooses to date someone younger than that person is...to an extent, the conversation about where the both of you are in your lives at the time when the relationship started to look serious comes up.
That aside, you did say that your career path would not suffer greatly...but how far are you willing to advance your career? If nothing is guaranteed and if you are not sure how far you'd like to advance your career then you should stick with the Fulbright. Also, if the person you are dating is telling you that the relationship will be on the rocks if you leave abroad for something that has much to do with the advancement of your career and life (which would also include him), then I think you need to really think about what else you might have to backseat in your future should your relationship with this person get to the settling down point.
Nothing is guaranteed and when it comes to relationships BOTH people need to be willing to support the other person. Once you settle down, a lot of opportunities get thin, especially if you know the other person isn't the type to be able to find some sort of balance for great once in a lifetime opportunities that the other in the relationship may come across.
How badly do you want this Fulbright? As you know the process to get to where you have is nothing to scoff at (not accusing you of doing so)
How important to you is it that someone makes a strong effort to support you in the advancement of your life?
...sometimes people support us but sometimes the support that people are willing to give have boundaries. Are you comfortable with the boundary that you see that the person you are dating is setting for you?
I hope my response gives you a different direction to take this in your mind.
At the end of the day, yes people could be disappointed but if you stay with this person, be benefits from your Fulbright too...settling down, you want to advance your career as much as you can if you're going to settle down...depending on what kind of life you want to live (not just monetary).
If you got this Fulbright, you WILL need to really think about what else you are willing to do for your personal life...which is understandable... I know some people who would give up a big opportunity for the good of their family. I will say, they have children factored into the situation. I am unsure if that is your situation.
....decisions like these also include deciding how much the other person understands your passions, sometimes sacrifices need to be made but they can be handled if both people are confident in the strength of their relationship. It will be a challenge but confidence on both sides is extremely important. There is a lot to be said for a strong foundation.
You both may want to discuss your fears with one another...you may have already discussed it but REALLY discuss it. :-) You both need to tell each other what you both think SUPPORT means in relation to each other/relationships etc!
