My mental health is struggling

I lost my Grammy in September and when I tell you she was my world, I mean it with everything inside of me. I am struggling so bad. Not only with this but with so many other things. I’ve been with my boyfriend for two years and he is THE BEST thing to happen to me. He is literally my rock, in human form. He’s been snap chatting this girl him and his friends play video games with. Like he will take random ass videos when we’re in the car and send them to her or take videos of our dog to send to her. Like they’re literally talking all the time. The other day he asked me how he would type out “mhmmmm” and I told him and I saw he was typing it to her. Whatever, that’s okay. He asked her to play video games and she said she was busy and he said “mhmm you never want to play” then she said she was busy and theyd play later” Then I saw she was saying shit the previous day like “I love when you send me videos. They make me laugh” like HAHA they make me laugh too, so freaking hard 🙄Guys, I don’t know where I’m going with this. I trust him, we have no problems. Our relationship is beautiful, honestly. But I have just become such an insecure person since I lost my Grammy. I am weak. I am vulnerable. I am naive. I am a fucking wreck. I have no one except for my boyfriend. I work 24/7 and go to college. I just feel lonely. I need help so so bad I am not okay. I know it’s okay to not be okay, but I don’t want to feel like this anymore, my heart just freaking hurts and I don’t want to live this life without my Grammy anymore. I was never an insecure person. I’ve always been such a happy girl. I never cared if my boyfriend talked to girls before, maybe I’m over exaggerating and over thinking their conversation, or how much they talk but I just can’t help it. I just don’t know how to help myself my hearts hurting to bad.