Need advice ! 😕😕

okay so today I woke up on this nice Sunday morning until I look at my phone and my boyfriends bestfriend follows me on Instagram likes most of my pictures and comments on one of them and says “ dam your gorgeous “ and dms me saying “ add me on snap 🔥” so I tell my boyfriend and NOTE I NEVER RESPONDED BUT HE ENDED UP FINDING MY SNAP AND ADDED ME so I was curious what his bestfriend would do if I accepted it cause I just wanted mu boyfriend to just get some answers from a fake friend so I accepted it and he snapchats me and sends me a Picture saying “ lit now I won’t be bored “ so I’m telling my boyfriend and my boyfriend just isn’t really caring and just stays quiet , NOTE : that I told him on the phone and he just said “ oh well dang “ like I’m not mad but dang he really doesn’t care 😕 I would be upset if my bestfriend did that and I told him that and he seemed careless

We’ve been having problems lately and him and I just haven’t been clicking well and I’ve been just upset and depressed and I can’t talk to my boyfriend because every time I do he gets upset or depressed and I help him and help him and I just need help what do I do ..

Someone help ..

UPDATE : his friend is still texting me and he doesn’t mind