@prayerwarrior02 I had a scare with this as well. For reference though, I am 36/male.
I was sedentary as a teen, then started martial arts and football my freshman year of HS. Football wanted me to gain weight, so I did. Went from about 170 - 200 lbs, developed a heart murmur and high blood pressure, so they wanted me to lose weight. I did, but have been very concerned about keeping my weight low ever since.
Martial arts kept me fit, but it was cardio intensive. Muscle training was pretty much body weight only and not super consistent. I hovered around 160-165 lbs for like 15 years. Covid was terrible because I got lazy with macros and ended up severely under eating, like 1400-1600 calories a day. That habit lasted a while - I either had no appetite or felt like I was too busy or tired to eat, so I didn’t.
About 18 month ago I was doing some calisthenics and weight work after training martial arts for a few hours. I was sore from the weekend, but figured I just needed to work and it would go away. Long story short, I ended up compressing a nerve in my neck and also gave myself a partial pectoral tear. 6 months of physical therapy, major upper body muscle atrophy, etc. I could do 150 push-ups in about five minutes and went to not being able to do more than two without a lot of pain. Same with pull-ups, dips, toe to bar leg raises…it’s still taking time to go back.
Anyways, I didn’t gain weight but my visible six pack had gone away (spent YEARS on that, I’m still mad!) and I just looked kinda squishy. A fitness gym opened behind my house and martial arts wasn’t really feasible anymore, so I signed up.
I have been eating about 2200 cal a day - still not enough, but a significant jump from where I was. Noticeable gains in strength. That six pack is still gone, but my overall body shape at least looks “fit” and so squishy. Weight went up to about 175, clothes felt kind of tight, and I panicked.
I have been told the same stuff you were - a lot of that weight is likely water weight from muscle inflammation. I was also told that lean mass gains tend to happen quicker than fat loss, and since muscle weighs more that can also account for some weight gain. I was still concerned that my pants were fitting tighter that I was used to, but was told that that’s likely a combo of my trunk getting more muscular first and that any fat tissue probably hasn’t come around to being reduced yet.
My trainer does want to bulk me up to about 185 before doing a cut back down to around 170 though, so I was told to buy some bigger pants in the meantime and not to worry too much