I’m so jealous, but am I being over dramatic?

So I’ve been with my boyfriend for 3 years now and he’s constantly telling me he wants to marry me and stuff but has not proposed or anything. He got me a promise ring but tbh I feel like promise rings are for kids in high school when they’re too afraid to tell their parents about an engagement or something. Well I’ve been okay with him not proposing and accepted the promise ring because I do love it and love the thought. But Saturday we went to his mothers house and I noticed a ring on her finger I’ve never seen and I just figured she was wearing an old ring or something but then she tells us she’s engaged. Her boyfriend that she’s been with for maybe a year proposed to her Friday night. Now I am so beyond thrilled for her and I’m so glad she’s happy but I’m starting to think my boyfriend will never propose to me and it’s upsetting because I do want to marry him. I love him more than anything but I can’t help but become more and more jealous when I see people who haven’t been together that long getting engaged and married and I’m just getting a promise ring after 3 years of being together and being grown adults. I haven’t brought it up to him because I don’t want him to feel pressured into doing it but I really am kind of sad that he hasn’t yet...😢