Could I be overthinking/:

So my boyfriend of 3 years has really started hiding his phone gets all protective when I reach for it or go near him on his phone. He literally leaves the room to answer calls, texts, messages. Everything takes his phone with him anywhere and everywhere. Now we have had problems in the past with trust due to issues I won’t go into detail about it. But am I overthinking/ reacting or should I be worried he is also Turing 18 next Wednesday and said he doesn’t want to go to town or anything with me. Even when I go into his work, (we work for the same company but different stores so everyone knows we are together) there is this one girl who looks at me and laughs every time she sees me and then runs out the back to him and they both come out laughing together. And he is so rude to me in front of all the staff. Side note I also have really bad anxiety and depression. So I’m not sure if it’s a gut feeling he’s cheating or I’m being anxious and the depression is playing up and I think that he’s cheating. Please help