Changing negative thoughts about how men see women

Throughout my life I’ve had certain experiences that have led me to very strongly believe certain negative beliefs about how men see and value women. These are some examples of the thoughts that I have noticed in certain situations:

I seem to have this general belief that men will always want to cheat on their girlfriends/wives even though some men don’t, because of whatever reason, maybe they don’t want to also lose their wife, maybe they just don’t have the opportunity, maybe they just do and no one has found out… That if they had the opportunity to cheat and no one would ever find out, they all would. The feelings this creates are distrust and suspicion. This one feels especially bad because I have a lot of male friends who are great people and would probably not cheat, and it feels like I’m just thinking badly of them behind their backs, which kind of is true I guess in a way. I guess there are also many women who would do the same, but somehow I believe there exist many women who wouldn’t.

My boyfriend once said to me he is following a certain celebrity on instagram. She is skinny, blond, tanned, has large breasts and almost exclusively posts pictures of herself in bikini. This really triggered me to compare myself with her and as I have brown hair (which seems to be seen as ‘inferior’ with respect to beauty by many men – this is actually a separate belief that I have adopted), light skin and small breasts. I really felt so hurt and embarrassed by this because I don’t seem to meet ‘the standard.’ The underlying thoughts are that these exterior features somehow make me

1. less attractive to men, 2. therefore less worthy and 3. more likely to get cheated on!

In other situations, the opposite happens. When I am at a social event where there will be people who I don’t know yet, I actually get sort of relieved when I believe that I am not the ugliest/least attractive women in the room, which is really awful and I also beat myself up about this.
I see appearance as an extremely superficial thing that shouldn’t matter, and I make an effort to treat people the same regardless how they look, but in my thoughts somehow it does matter a lot to me because I think it matters most to men and I care about how I am perceived by them.

These thoughts and beliefs are getting me in all sorts of trouble as you can imagine and are really keeping me from enjoying my life. It has really clouded my judgment towards men. I am just interested to read some other ways to think about men and women and how they relate to each other. Whenever I try to write down a positive intentional model to replace it, it feels like I am trying to force myself into taking too large steps. The feeling that I would want to feel more of in this context is relief, by knowing ‘it’s all ok’ and I don’t have to worry about being inferior to other women or being cheated on. Like a sense of calmness and peace. Currently I haven’t found thoughts that really provide this for me yet, so if you could help me out with getting started that would be amazing. Thanks in advance!