Failing

I would suggest first just trying to stop the damage by trying to maintain your weight. I’m sure because you gained you want to immediately start losing again, but if you really want to turn things around, a smaller change to just get you to stop gaining and start eating in your maintenance calorie range may help more than more radical attempts to get into a deficit.

Think of it like this - if two months ago (when it had just been one month) if you had been able to just maintain for the next two months, instead of continuing to gain, think of what a better position you would be in. Same thing with one month ago - if you had been able to put the breaks on and just maintain but not gain - I’m guessing you would be in a better position than you are now.

You can do that now before 3 months turns into 4, 5, or 6 months. You really haven’t done much damage - 11 pounds is not a ton, but before you can worry about losing again, stop the gain by maintaining for a month or two. Once you have that under control I’d say think about a deficit again.