This is the question everyone wants the answer to. And I am not sure that any one human, or even all of them, can answer it. But how can I experience permanent well-being, in spite of life's hardships?
It seems, that your problem with well-being is that there are hardships. So if there were no hardships I suppose you'd be well by you definition. Hardships are a severe difference in what you want and what you have. There is a notable philosopher, that worked on that precise front: Diogenes of Sinope.
He proposed not working on the "having side" but on the "wanting side" of the equation. He defined some basic needs that must be met (food, drink, clothes, shelter, sex). Anything above that he considered to be superfluous and you should try not to want it. It is nothing wrong with having more than that and enjoying it. You just should not want it.
According to legend, he trained himself to get rid of those superfluous desires: He bathed in the hot sand in the summer or hugged the snow-covered statues in the winter. Also he bedded for money from statues to get used to the dissatisfaction of not getting what you're asking. His lifestyle was so repellent to his contemporaries that they called him a dog ('kýōn'). He wore that name with pride and became one of the founders of Cynicism.
Permanent - there is nothing in this world that is permanent. Everything is always changing.
Well-being - There are as many people in this world that enjoy being miserable as there are that enjoy being happy. If you had no sense of being 'unwell', you would have no sense of being well. You can have no sense of well-being without the sense of not having been well.
The sense of well-being or misery lies in the senses. True well-being lies going beyond the senses. There is nothing permanent in the sensual world.
The only way to experience perpetual "any feeling" is to continually have stimuli that cause that feeling and said stimuli must also adapt to your own bodies ability to get used to its environment.
Example: A certain smell that is pleasant is constant. You will eventually get used to that smell and stop noticing it. In order to keep noticing that smell it must continue to grow stronger as you continue to get used to it.
The same is true for any feeling that is a result of any certain stimuli. So, if your stimuli is constant, then you will eventually get bored with it.
Conclusion: It is not very likely to be at all possible to enjoy permanent "any feeling", whether that feeling is good or bad.