A man being strong in his heart tends to mean he is in control of his emotions. Being in control of your emotions is not a today thing. It is a next year thing. Planning ahead and being prepared enough you can appear to be in control of your emotions almost all of the time and only some of the time does it happen by dint of immediate effort.
A thought leads to a decision, so start thinking that you want your goal. A decision leads to action, so start deciding that you want your goal. Action leads to habit, so start acting towards your goal. Habit leads to emotional match between actions and emotions, so build habits that moves towards your goal. This process results in your being in control of your emotions - Strong in your heart. It can take a year for the follow up on any one decision to bring your emotions on the topic into match with your intention on that topic.
You have already followed this process for accumulating material prosperity so you already know how to follow the process.
Here's what to decide next - You value net worth from investments. You value retirement income from investments. You divest yourself of physical goods that are not consistent with your new retired lifestyle. To the extent that your stuff weighs you down you drop emotional attachment to stuff. It's not the stuff that you value. That stuff only came along for the ride because earlier you mistakenly correlated it with net worth from investments. Your stuff is not your wealth, not the source of your wealth.
I've gotten to the point of being almost Zen about my stuff. I have a few Xerox paper boxes worth of mementos that I intend to keep forever. I have a room full of books, computers, you name it that I use but that could be trimmed out of my life by deciding to not use it any more. I have a half of a closet of clothes (maybe more like a third of a closet) that I could trim to under half without batting an eye. There just isn't much stuff that I'm attached to any more.
My wife remains attached to a lot of our stuff, but as the year pass she sees the benefits of my attitude. The amount she's attached to gradually drops. We are still far from being able to move into a fifth wheel to live on the road, but we'll get there eventually.