I cannot recommend mindfulness enough, as already suggested by many others in this thread.

I think, you said you are already in therapy? In this case, I would definitely talk with your therapist about this and things you want to adopt beforehand. If you want a simple concrete tip, you could try the “mindfulness coach” by the US department of veteran affairs. I liked it a lot and the apps from there get good privacy recommendations from mozilla.

I am a bit suprised by the many people recommending to just stop giving fucks. Is this what you really want? Or do you just want avoid the emotions of taking control?

You do not need to be that hard to yourself when your feeling “wrong”. Yes it is probably better for yourself if you don’t overreact. However you cannot really cotntrol your feelings. So it is still better to accept your anger. First, as you said, it drives up the frustration, because now you are also worried about your feelings. And second your original emotion wants to be “noticed”. I read and experienced a few times myself, the “wrong” emotion disappears often quickly when you accept it. It is an essential concept of mindfulness, to accept your emotions.

Edit: As far as i understand it and experienced it, saying to yourself “no i shouldn’t be angry about this” won’t change your thinking

relevant xkcd

I don’t know your exact experiences, but I had a similar feeling in the past. However, recently I noticed it was a lot of how i behaved to them. I started speaking more openly with my male friends and noticed, they also value my emotions. The main difference was, that my friendships with women started on an emotional level making it a lot easier to open up for me. With my male friends, I needed to just say how i feel, which i have not dared for a long time. My own stereotypes probably played a larger role than the gender of the people involved.

However as others have said, if they do not take you seriously when you open up, they are bad friends. (Edit: Bad friends is a bit harsh, more like friends for having fun together, not to rely on. This is also nice even if it can be hard to accept)

Don’t be so pessimistic about it, i thought as you do. However, if you meet a person fitting to you, it is of no importance that you have no experience. I had my first date recently, probably ten years later than most. While i was embarrassed, it was no problem for her and she was very considerate to me.