gonna be a heck of a climb back
There is nothing we can do to avoid the curve balls life throws at us sometimes.
It's not our fault. However it is true that we play a part in that we might not have the knowledge and experience required to successfully manage problematic situations in our lives when they happen. As time passes, if we put the work in, then the problematic situations become valuable lessons.
It sounds like there are at least two problems you are not addressing.
1) Finance.
You can spend time in self reflection figuring out why you are in this hole. That is the most important thing because without being able to grow you might very well repeat the same behavior later on. Did you spend to get happiness? Fill an emotional hole etc?
2) Your woman.
Have you based your happiness and/or identity in her or just being in a relationship in general? You might be attached to the part she plays as your partner rather then her herself.
Are you sure you really love her or are you afraid of ending it? A lot of the time it takes a divorce for men to learn the truth about women and themselves. With the internet it's all out there. Men have been comparing notes and noting the similarities in their experiences.
Women will respond to men they respect. Her behavior tells you that she does not respect you right now. It might also be the case that you do not respect and love yourself which is why this situation is carrying on. Being a nice guy is what Hollywood tells you to do but it's not productive in the real world.
Looking ahead you need to be happy with yourself and know exactly what you want from a relationship so you can share that with the next woman and let her know the boundaries.
I had to spend a lot of time figuring things out after I lost someone recently. The good news is plenty of information is available to help you think it through.
The divorce stats should tell you something is wrong somewhere so it's up to us to figure out where because there is too much $ involved and ingrained anti male preference in the system now to expect anyone but ourselves to help each other.