So it all starts with you. This is not an egocentric perspective at odds with the teachings of the Buddha. The first teaching of the Buddha, the Four Noble Truths, is about ending your suffering; not someone else's, yours. That is the focus of all the Buddha's teaching. Yes, we are taught to offer others joy and have compassion for others, but the central reason for that is that that is how we offer ourselves joy. If we are mean-spirited towards others, that energy is toxic and so we will not experience joy.
What, you may ask, about the teaching to be selfless? But that teaching does not mean that one should not think about one's needs. This is often lost in the teaching. It means that you don't do something solely because it meets your needs and never mind how it impacts anyone else; it means you should not be selfish.
So back to not harming yourself. First, this does not just mean physical harm. No, I am talking here about psychic harm. The harm that we inflict upon ourselves every day through the thoughts of our ego-mind.
The ego-mind is the source of all our emotions, judgments, cravings, and attachments, and they are the cause of all of our suffering, our fears and frustration, not events or aspects of our being. Every time the ego-mind takes control of you, you are beset with suffering and in this way you harm yourself.
But you may say that you have no control over your ego-mind. It is an inseparable part of you. It is your very being.
Not so. While you undoubtedly feel that your ego-mind is an inseparable part of you, that's not the case. You may feel it is your identity because it's the only identity you've known your whole life, but it is not your true self. One can free oneself from the control of your ego-mind. Indeed, that is central to the Buddha dharma. You don't get rid of it, just rid of its control over you.
The first step is to acknowledge that your ego-mind is the source fo all your suffering and that it is not your true self. For as the Buddha said, "if it causes you suffering, it is not you, it is not yours, it is not your self for your self would not cause you suffering. "
Once you acknowledge that, there are various techniques for freeing yourself from its control, all which you will want to use because the ego-mind has so much power over you. A good starting point is the practice of saying, "Not me!" to your various emotions, etc. See my post, "Not Me - Peeling Off the Layers of Our Ego-Mind." For a full treatment of the whole process, see Chapter 3, "Freeing Your Self," in my book, How to Find Inner Peace.
While you are freeing yourself from your ego-mind, you want to reconnect with your true self, which is your heart. This is not as simple as it sounds. But when you are able to make that connection, you will find that your heart is light, love, faith, trust, compassion, humility, gratefulness, joy, contentment, strength, courage, and wisdom. Not a bad combination!
When you connect with your heart, you will have no negative thoughts about yourself, you will do nothing that harms yourself, and you will do nothing that harms others. You will be at peace and experience joy.
Again, the process is described fully in Chapter 2.2, "Our True Self is Our Heart," in the Inner Peace book. I just realized that I have not written a post on the subject. One will follow in the near future. One relevant post is, "Avatars - Their Usefulness. "
As stated above, your primary purpose in life is to offer yourself joy. Once you have freed yourself from the control of your ego-mind and reconnected with your heart, you will be able to offer yourself joy. And how do you do that? You take joy in each passing moment regardless what is going on, be in touch with the positive energy of your heart, release all desire that your life be different in any way from the way it is right now, be aware of all you are grateful for, love yourself unconditionally and have compassion for yourself. That is how you offer yourself joy.
May you experience peace and happiness.