7 months together, pregnant, engaged, baby, love her dearly, rocky year, a lot going on. Off course there is, world win romance a child and a lot of responsibility. Good for her that she still loves music, must be a release for her yes?
There is nothing wrong with living your life, being assertive, capturing things within your life "you" personally wanted. Didn't you as well?
Firstly, you have to start with the "many break ups" in recent months, ascertain why, what was the differences how can that change what can you do.. You say you really love her.
Secondly, understand that you are both living in the present hopefully to have a future, nothing wrong with memories.
It's good that before she had the baby she told you of things that belong to her because she "shared".. You didn't suck it up, a person belongs "with you" not to you.
Your problem is, not jealousy, your problem is not knowing what constitutes a relationship, makes a relationship happy, going through life in the present..
Memories do not mean that you are living in your past, it's called a memory. Any memory can make you smile, get over it. Honestly and work on laughter, fun, togetherness "now" in your present or you may have to realise there will not be a future.
By the way, "jealousy" and you called yourself the hulk
So you must think you are a bit of a catch... Believe it.