> I'm not sure how to build compassion for myself ...
I didn't understand it either at one point; I had no idea what it meant or where to start, and was taught to snear at that sort of thing (that was the biggest mistake of my life). If you're stuck, try a therapist - they can help you get started.
I can't really offer much over HN forum posts and obviously I don't know you well enough to offer advice (and I'm not an expert!), but speaking generally from one person's experience: One fundamental that might apply is that what you write about is mostly focused externally, especially the focus on a romantic partner.
It's completely normal, and in fact it's inevitable and extremely health: every human needs love, support, compassion, etc. We are social creatures - we are not built to be alone.
The needs never go away; ignore them, supress them, deny them, and yet they still will come out. There should be another physical law with those of motion, thermodynamics, etc., the Law of Conservation of Emotional Need. If you try to suppress them then they will dominate your emotions and you end up acting out on them anyway, usually in an unhealthy way at a bad time, often without realizing it. Our bodies will not be denied; they take over and almost force your hand - drinking, etc., or whatever immediate relief is available, healthy or not. Via relationships, we demand their fulfillment by others; the others become mere objects (as in, objectification) who exist to fulfill our needs.
Another principle is that if we feel vulnerable, powerless, or or worthless inside, then we look for much more externally - from unhealthy romantic partners, from drugs, from workaholism, from skydiving, from video gaming 24/7 ... different things for different people.
Those things we act out on, and those we look for externally, are signals of unfulfilled needs - real, healthy needs that we've neglected. To care for them, we must first know ourselves - really be honest. If you tell yourself, 'that's too ugly, I don't want to talk about it' - it's going to be hard to take care of the need, and it's also pretty awful; imagine a partner or a parent rejecting you like that (unfortunately, many people can imagine that very well - don't listen to those people, who probably are repeating their own experiences). We need to learn to love it all, ugly, deep, serious flaws too. Everyone has deep flaws, so that doesn't exclude love. IMHO it's the only thing that makes love meaningful - enjoying the successful fun parts is easy; in fact it doesn't even require love.
One of the biggest benefits is that, even as our external life changes - people, jobs, crazy politics - your 'best friend' is always there and can't be taken away by anyone, unless you let them.
Another benefit is that a healthy relationship with yourself enables genuine, healthy relationships with others. To get a bit mushy, if you are going connect heart and soul, that connection has to go through your conscious self. It's a serial connection (this being HN!):
your inside - your consciousness - their consciousness - their inside
I hope that helps!