Dear Stigsrud,
"My fiancé tries to stop me from eating"
That was the title of your post, but your post does not say that--rather it says,
In this case, at a 275 squat, age 24, 6'1" height and 215 bodyweight, most folks on this board would endorse getting stronger and eating enough to do so. Coach Nick has told you above what your specific approach should be (increase calories slowly, get to 405 squat).
If your fiancé wants to cook meals for you that are too small, that would be sad--but it sounds like she just disagrees and worries about you and is telling you that.
It is not always a cause for concern that wives (and future wives, such as your fiancé) occasionally disagree or worry (possibly often!).
There's nothing wrong with listening to your fiancé--your question should be: (1) is she pleasant about the disagreement, (2) will she listen to your reasons for your actions (see Coach Nick above) and change her mind on the basis of your reasons, and (3) if she continues to disagree, can she accept your decision (about your own body in this case!) and be content with it.
If your fiancé can listen and be pleasant and accepting, even in a disagreement, then you have no cause for concern--you are blessed!
Best wishes to you and your fiancé, and good luck on your NLP!