Lexapro and possible side effects?

Hello, I'm new here so I'm a bit nervous to talk about this kind of stuff but I don't really have anywhere else to turn.
I've been on Lexapro for 6 months and about 3 months ago I dipped back into similar thoughts and attacks I was having before my prescription. I thought perhaps it was normal to have a small setback and it would be fine but sadly the amount of anxiety/depression I was having slowly increased until I finally mentioned it to my doctor a week ago. She increased my dose to 20 mg and so far I feel slightly better (though I believe part of that is placebo) but I constantly feel like there's screaming inside of my head. Like I have this frustration and anxiety that isn't being released and is coming out in the form of just screams in my head all of the time. Has anyone else experienced this? I am also taking phentermine which I have taken for the same amount of time and honestly I no longer feel any side effect from but wondered if perhaps that could also be a cause.
I don't know, I wonder if dealing with this is better than my attacks from before and honestly it's a toss up :/