This happens me a lot as well, especially at those "stalled, got add an extra 300 cals" mile stones, where I had to up my portions. When it seems to be from a certain food, I sub it out for something else (rice making me gag, switch to potatoes) for a few months, usually helps.
But if it's one of those times where it's happening WHENEVER you eat (these are the worst), I have a few solutions. FTR, these are what I, myself have done. I'm not a doctor or anything, so take anything I say as nothing more then a personal anecdote.
1) Eat dirty, just a few days. I always gag when constantly eating bland meals (beef and potatoes, chicken and rice, tuna and rice), but I noticed I never gagged eating a Whopper from BK. Just eat roughly the same macros and cals as you did when eating cleaner, but from some shittier sources. No it sounds dumb, but it gives me a psychological relief I think...
2) I'd say drinking shakes is a good way to do. A blender is pretty cheap, and it's harder to throw up something that down the hatch in matter of seconds.
3) When I wake up in the morning, often times I have to train soon after, so I drink a shake. For some reason, ANY food right when I get up makes me wanna throw up. What seems to help me is, before eating, drink a few glasses of water, and maybe a can of diet soda. I have no idea why it makes it easier, but it does
4) If you have time, do a bit exercise before hand. I can usually put away most of my food for the day those few hours after lifting without an issue
At the end of the day, though, I think it's just one of those issues that, when forcing a lot of food into your body, you gotta deal with.