I (27M) have been in a semi long-distance relationship with my girlfriend (20F) for about a month now. In my past relationships I've always been extremely emotional and affectionate, while my gf is quite the opposite- she's not particularly fond of showing affection directly, and has even asked me to tone it down a bit when it comes to expressing my feelings for her.  
I've also struggled with low self esteem since forever, especially in regards to my appearance, because for most of my life I was quite overweight, and only recently  after many months of gym I'm close to my target weight of 80kg. I do my best to not show my low self esteem, since I know it's usually something frowned upon, especially in terms of relationships.  
My girlfriend tends to make a lot of remarks while watching movies about some male actors being hot, attractive, or DILFs (xD). I am aware that she's just saying that without too much thought behind it and definitely with no intention to hurt me in any way, so usually I just ignore it, or sometimes even agree with it.  
Lately we were exchanging some selfies and she was rather critical of any photos I'd send her. She'd say that I   look "dead inside" or that I have a "long face". It took me a while to accept that she's just not the type of person to give out compliments.  
Today there was a repairman coming in to her house to fix something, and while texting me she casually mentioned how he's pretty hot. It was the first time she talked like that about someone who wasn't a movie or fictional character, and combined with my worries about my appearance and the disappointment in regards to selfies, it kind of sent me spiraling down.  
 I told her that I have to bring it up that I understand that she doesn't mean anything serious by it, but calling other guys hot while also not showing too much affection towards me makes me feel really bad. I asked if she could tone down the comments about other guys.  
She apologized and told me that she did indeed feel weird telling me that other guys are attractive (makes me wonder then why she did it anyways?), and promised to keep that for "girl gossip" from now on. She also said that I shouldn't be worried anyways because I'm a solid 7. She has also been quite sweet to me today, wanting to spend more time together and texting me a lot.  
Because of my mental state I'm having lots of trouble dealing with this situation. My therapist encouraged me to communicate things I don't like in the relationship and to set my own boundaries, since usually I'm a very subservient person who avoids any conflict and mostly goes with what my partners want. On the other hand, my friends have told me that I "shouldn't be projecting my insecurities onto my girlfriend", which makes sense, since the whole reason these things affect me is because I'm still self conscious about my appearance.  
Now I'm scared that what I did wasn't setting boundaries, but rather some sort of emotional manipulation that will only serve to distance us away from each other. Also now that my gf knows that I'm somewhat self conscious about my appearance, I feel like she will, indeed, start seeing me as less attractive than earlier. I'm not even sure what I should think about being a "solid 7". While I would embrace it as a compliment from anyone else, hearing it from her makes me question if I'm good enough. Overall I feel like I overreacted and fucked up my relationship because of what I did /o\