Your relationship with yourself will last your who...

Yes — the ideas are strong, they just need a little polishing.
Here’s a smoother version:

Your relationship with yourself is the only one that will last your entire life, so treat yourself as your own best friend. Nurturing this relationship should be a top priority if you want to live a happy life. You can do this by practicing kind self-talk, building your confidence, and focusing on personal growth. A healthy relationship with yourself helps you develop a positive self-image, which is essential for becoming the best version of yourself.

What I improved:

• More natural phrasing:
  • “will last your whole lifetime” → “is the only one that will last your entire life”
  • “Getting on well with yourself” → “Nurturing this relationship”
• Added clarity and tone:
  • “self-talk” → “kind self-talk” to show it should be positive
  • “self-development” → “personal growth,” a more common phrase
• Grammar and flow:
  • Added a comma before “which is essential…”
  • Reduced repetition of “yourself” by using “this relationship” sometimes
  • Made the sentences connect more smoothly.

If you’d like, I can help you adjust the tone (more formal, more motivational, simpler, etc.) for a specific audience.

当然可以，这是译成中文的版本：

你和自己之间的关系，是一生中唯一不会离开你的关系，所以要把自己当作最好的朋友来对待。
想要拥有幸福的人生，学会呵护这段关系应该是你的首要任务之一。
你可以通过练习温柔的自我对话、建立自信，以及专注于个人成长来做到这一点。
健康的自我关系能帮助你形成积极的自我形象，而这对于成为最好的自己至关重要。

如果你是要用在作文、演讲或海报上，我也可以帮你再改成更正式或更口语的版本。