"Everything is bitter, only self-reliance" is a Buddhist term, which means that in this world, all sufferings need to be faced and solved by themselves, and no one can replace them. Suffering in life is inevitable, but we can overcome it by ourselves.

First of all, "everything is bitter" expresses all the pains and tribulations in life, whether physical or mental, which are inevitable. These sufferings may include birth and death, parting, loss, frustration and so on. No matter what environment we are in, no matter who we are, it is difficult to escape these pains.

Secondly, self-help emphasizes the importance of self-help. This sentence means that we can't rely on others to overcome our difficulties and pains, we must rely on our own strength to solve them. This kind of self-help power includes one's own wisdom, courage, indomitable spirit, self-reflection ability and so on. Only through self-help can we truly overcome difficulties and achieve self-growth and promotion.

Finally, the phrase "All things are bitter, only self-seeking for more happiness" also expresses a positive attitude towards life. It tells us that although there will be many difficulties and challenges in life, we must face them firmly and overcome them with our own strength. Only in this way can we really grow and progress and realize our own life value.

In a word, the phrase "everything is bitter, but you have to fend for yourself" means that no one can solve the problem for you in this world, only you can save yourself. In the face of difficulties and challenges, we must firmly rely on our own strength to overcome them, so as to achieve self-growth and promotion.