I don't think the (age) of the men is your problem. Selecting the (wrong) men is your problem. You need to find out what traits you want in a man period. (Regardless of their age).
Young men break women's hearts too.
The older one becomes hopefully the more mature they become. You should never mistake one's "sweetness" or "kindness" towards you to mean they are "in love" with you. Most people bend over backwards to impress their (new) love/sex interest. A mature person understands there is always an "infatuation phase" to relationships. See a person's "authentic self" before emotionally investing in them.
Each of us (chooses) our own friends, lovers, and spouse. Nothing happens until you say "yes". If you go to the grocery store to purchase an apple but you buy an onion instead, whose fault is that? Do you curse the onion for not being an apple? No! You learn to become a better shopper!
As I stated the man's age has nothing to do with how he treats a woman. You need to create your "shopping list" of traits for your ideal mate and then have the discipline to stick to it.
"Never separate your mind from your heart when making relationship decisions. The purpose of the mind is to protect the heart."
Best of luck!