So the boyfriend was this younger guy? and not abusive? That's not dangerous, except as an unconscious way of holding off on pursuing another marriage so fast. You're both in the age 30 transition, so it really makes sense for you to be relinquishing your young adult music career-as-experimental-adulthood. She's just getting into her age 30 transition, so having to wait is pretty likely. I asked about her exes because she might have different expectations for how her man should look and be that you don't fit. Is she used to being pursued?
How many months were you courting before this first weekend together freaked her out? What is she studying in college? How old are her kids? How much do you know them? You're lucky she's already had the younger guy, because you're not the first post-marriage bf, so some of her healing needs have been met. But her reaction to your signs of possessiveness shows a pretty raw wound. You could send her little love letters at slightly irregular intervals, like 4 days, then 6 days, then 3 days, based on things that happen, and in them share your artistic sensibilities to things and people you experience, and close with some loving thoughts or reminiscences about your time with her. Depending on how she responds, you could ask her to something you think would be meaningful to her and you both (art is meaningful) after some letters. Absense makes the heart grow fonder IF you're thinking about the person who is absent, and if she gets letters that come as a surprise, she'll start thinking about you more often, and probably look forward to more of them (which is why you keep the intervals slightly irregular, to intensify her attention through anticipation). This is emotional manipulation, but it is also emotional expression, and you DO think about her often and fondly. So you're just sticking you neck out to risk it that she'll like to think about your thoughts and your artist/musician's perception of aspects of life that she might like too. You can add that you're not expecting her to respond unless she wants to..... but the fact is, every artist is inspired by love, and you are too. And you are merely asking her to be your muse for a while, so you can "muse" about things that inspire and move you, and you imagine might inspire or entertain her too.
Sorry but I have to get my sleep tonight, so I won't be working on your responses until tomorrow.' I wrote that last paragraph above right after signing off down here. So that's my own version of "OK I don't know what to advise to help you, so I'm giving up for tonight." And it's not a bad idea at all, if you have the courage (coeur=heart, age=stuff you have in your heart, or heart-strength) to let her be your muse and let your heart show. Love is a solo-sport in each person's mind, and you can have yours even if she's not ready enough to share hers--but you can also ask her to tell you to cease if she doesn't want to hear from you and your sensitive response to reality--but I wouldn't offer her that option until after the second love letter. How many people get any more chances to write love letters anymore? But do tell her at the outset to pretend she's getting your letter in the mail, so she doesn't have to respond in any short period of time or with any particular type of response.
Perhaps you write poetry. I wrote 10 or 20 poems in the first 6 months I was courting my wife in 1984, before we moved together at year's end. She was an English major, I have a PhD in German Literature& European Humanities, and I knew I wanted her, that she was the best woman for me that I'd ever seen since my first great love crashed when I was 29, and I was 41 when I met her. My first poem was called "Readiness is All" or "Taking a Chance on Love." and it used the analogy of the baby bird on its first trial flight from the nest way high up in a tree. Poetry's great when you have a really willing audience of one special beloved. But love letters will do fine--just don't go making a goddess out of her until she's willing to spend more nights in the nest at your place. Write about how beautiful the world is when love is in the air.