There's nothing wrong with backing out of relationships if you're unhappy. Anyone chooses to stay in an unhappy relationship is choosing to be unhappy. Define "challenges".
Verbal/physical abuse or cheating aren't just "challenges".
Each of us is entitled to have our own "deal breakers" or boundaries.
Having said that if you feel you are walking away from "happy relationships" because you fear one day the person you're with won't want you so you leave first....etc Then that is an issue only you can resolve within yourself.
You asked: What can I do for my spouse to love me more?
Each of us (chooses) our own friends, lovers, and spouse.
When it comes to love and relationships most of us (fail our way) to success. If this were not the case we'd all be married to our high school sweethearts! People don't leave people they're "in love" with.
The goal is to find someone who loves and appreciates you for who you are. You also want a mate who (already is) the kind of person you want to be with.
Very few people are walking the streets with one hand raised in the air screaming: "I'm looking for someone to change me!"
Staying married for the wrong reasons is just as bad is getting married for the wrong reasons.
At the very least a "soul-mate" is someone who actually wants to be with you and (vice versa). If you want out then he's not "the one".
Communication is the GPS for relationships. Find out if you both still share the same values and have the same goals for the marriage. You're either "growing together" or "growing apart".
There are only two ways to experience joy and peace of mind in relationships: We either get what we want or we learn to be happy with what we have. Accept them as is or move on.
The world may not owe you anything but you owe yourself the world!