Stopped losing weight

If you increased your exercise in the past two weeks, you're probably experiencing water retention from that. Otherwise, are you counting calories and logging everything as accurately as possible?

Congratulations on the weight loss! I advise that you divulge your daily calorie intake, your exercise program, your TDEE, and your macro distribution. That way we have enough information to offer informed comment.

First : congratulations on losing that weight.
Second: I'm in the same boat. Stuck on a plateau since March, after losing 50 pounds. I keep nipping and tweaking the diet, trying supplements and so on but I'm still not losing that last 20 -25 pounds.
My fall back is thinking "I'm still better off than I was before".

First, congratulations on the weight loss, huge accomplishment.

Secondly this statement you made: "I might be gaining muscle since my diet consists of low carb and high protein+fat. Have this happened to any of you?" Is not an accurate statement.

You only gain muscle in a deficit that tapers off fairly quickly as long as your deficit is NOT too aggressive (more than 2 pounds per week), you are getting ample protein and progressively working your muscles to activate muscle sparing. You can gain min muscle in a deficit and what you are left with through your weight loss is maintaining those muscles.

Next you are losing a good amount of water weight in the beginning of doing LCHF. So keep what you are doing and great job!

edited to add: your weight loss is not stalled or stopped, you have increased exercise so this may entail some water retention on the scale, its only been two weeks of this LCHF diet so you are probably still adapting to this way of eating..