Fiance said this during foreplay, am I overreacting?

My fiance and I were getting pretty dirty last night. I just got off of my period so I've definitely accumulated tension during that time. I was super horny, definitely at a 100%. So basically long story short, I have been with this man for going on 6 years. I have had a few occurrences of him talking inappropriately with other women and then trying to lie his way out of it(I only ask when I know, so why lie?). I chose to forgive him, there was two occasions 1.3 years ago and 2.5 years ago.

Anyways, so we're getting down and dirty and hes shoving an awesome dildo in me while I'm going to town on his 🙊 So, he's dirty talking and then says, "gosh baby before we get married in December I want you to find a girl and fuck her with this dildo while I sit and watch". LITERALLY I was so freaking livid, I went from 111000000%%%+ to 0%. Im not secure enough in my relationship like that anymore. I also don't appreciate the fact he wants me to sleep with someone else while he watches. Whats even more fucked up to me is that while I'm sucking his dick thinking about how much I want him to slam it into me, he's sitting there imagining me and another fucking girl. I didn't yell at him or anything. I stopped and said "are you forreal" and he wanted me to keep going but I didn't. He told me that I ruined the sex, and I said "no im not the one who ruined anything" he also claimed that just because he said it doesn't mean he wants me to actually do it, im not stupid especially since I remember one of those incidents pretty clearly. Then we didn't say anoyhrr word to each other. My feelings are still pretty hurt this morning. He told me "can you stop being depressed im trying to have a good day, you have that look on your face" and I didn't argue or anything and just simply said "I'm fine" then he got upset and told me, "I just won't talk to you much today.". My feelings are really hurt...... Im still having a hard time getting over the past and when I finally think my mind is going into a good direction he says something like that. What do you ladies think? Am I overreacting? Are my feelings justified? Idk. Im just trying really hard to not be insecure but how can I be when I feel like I have to be someone else or the fact that I in general just want to be someone else. If I had everything on my body that I wanted and liked maybe I wouldn't feel so insecure. He doesn't call me names or anything and always calls me beautiful. But at what point is just me and the way I am enough.