help please

I struggle with insecurities and trust issues. my husband has never done anything to deserve to be mistrusted, but i feel distrusting of him. i mostly think it's because he's not very involved emotionally and I feel lonely. well, I was going through a hard time a month ago and I noticed that my husband accepted an add from a female co worker. I told him I felt uncomfortable and that I wish he just would have told me but he said "thats not how it works." they don't talk through text or message. today, I saw him share a meme and she commented on it and he replied back and I felt very hurt and angry. it was innocent I think, but it still bothers me especially since he knew how I felt about him adding her in the first place.