Guy Advice?! 🙈

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Hi so this is my second relationship but honestly my first real experience with a guy. He's the first guy I continually sleep with. I'm 20 and he's 21. We've been together for almost a year. He's my best friend. We did go from BF/GF to no label. I was upset at first but my friends got involved with our relationship because they'd see me upset when we went through some drama a few months ago. He met up with his ex over spring break. I was crushed. We continued to still do what ever we did in our relationship, there just wasn't a label but also paranoia. Over the summer we'd still hang out. Yes, we have sex. We said we're good friends who have fun. 
When we were BF/GF he was the one to ask me if I loved him and I said yes and our relationship was great but we got into drama which it was his fault and my friends then and still hate him. They constantly shit talk him but I love him. Recently he told me he loves me. He also has been buying me little gifts like lingerie and he just turned 21 so he bought me hard cider. He never did this when we were together. He came out and said he loves me first this time. He told me he cares so much about me and that we have fun together. How we've been together for almost a year. I told him I love him too. 
A week later I told him I don't believe him when he tells me he loves me I told him I have such bad trust issues I can't even trust my friends. He doesn't like my friends either. He's the one I go to when I need a break from then but then they shit talk him 😞. 
I told him I'm scared he's using me for sex because well he bought me sexy underwear and spicy dice lol. I cry a lot too with him and I was crying while talking to him about this before bed. He's like: "I'm not going to bed until you tell me what's wrong." He told me he's not using me and that I'm the only girl he's been sleeping with for the past year. I really want to believe him and I think I do but there's a part of me that doesn't. We're close with his roommate and his gf. We all hang out on weekends. 
We are a lot more flirty and fun now that he's said I'm the only girl he's been with. He does keep checking his phone randomly but I try not to worry about it. He's being very affectionate and cute. Smiling and laughing more because we're having fun. His actions are matching up with his words. I know I love him but do you think he really does love me? My birthday is on Tuesday and he said he has a surprise for me and that I'll love it.
My ex who said shit about my family contacted me last week a year later after we broke up. He wants to take me to lunch to catch up. It's like the tables have turned. I think I want to go just to see what my ex wants. It sounds like he's treating me so I'll get a nice meal. The right thing to do is tell my bf right? He didn't tell me he visited his ex and her family until after he did. I was so hurt and I have an opportunity to do what my bf did to me but I feel like I can't. Please help! 😳😰Â