Should I still be concerned about my bf's relationship with other close "friends"?

8months have went by so fast and our relationship is strong. However, I still feel gloomy, nervous andinsecure whenever he sees or talks to other friends. With guys it’s all smooth and alright but with another girl that he considers a close “friend” really makes me seem as if there’s something about them. Months into our relationship he told me the day before he was gonna hangout with her friend from school. (Someone he hasn’t seen or wanted to catch up on things) As that day came by, the only time he texted me was in the morning to say, “Good Morning” and everything else we text before he want to school. As the day went by I got no texts, no calls, nothing to tell me that everything was okay and whatnot as he always informed me on what was going on. At this point I started to have a meltdown. I couldn’t text him or tell him because if I tried he wouldn’t answer..and he didn’t. I called my friend and told her the story then I texted him how I felt and he didn’t like how it sounded when I explained to him we needed to talk. He gave me a brief things they did for the day and let’s just say it sounded like a date… ._. The stuff he did with her..just don’t make sense. Going out to lunch, going to the nail salon…regretfully..?? Taking a stroll and then going back to his house to play video games. With all this said and done he waited around for her and didn’t mind the drive and where she lived. But when it comes to me, “Oh I don’t want to go far, blah blah blah” I call BS on that. if he can for FRIEND then hell he can for his me; His GF. I’m just shaking, because I can’t take the pressure and he;s been my first…but should I still be concerned because I saved the texts from his phone to me so he understands what happened..

The other thing real quick is on new years eve we hungout at a friends party. All went well until he was working on my computer he brought over, another girl he knew from school constantly went back there to talk with him, everytime I came out to the living room. I was triggered by this with jealousy, wondering to myself, “Why is she always going back there?” I confronted him about both subjects and different girls btw and he told me nothing happened. He told me, “she just wanted to know things and how the computer was”. Right from there I just went silent and he snuggled me..saying my name over and over..I just couldn’t bear with it since then I found a book. A mini notepad as it seemed and it had a sentance or paragraph with this girls name in it. He took it from me and torn out the pages… Should I approach him on that? Why did he tear them out? Why did he take it thinking “Oh shit!”? Like I’m territfied to approach him. I’m sorry for the long block of text, but I need support and help on this. I’m depressed and my bloodpressure is high, I’m having panic attacks by thinking about all this :/