I wonder I am a failure. I got two RA offers after my BSc. And few months later, I got an Mphil offer. Since then, nightmare begins. The laboratory I worked in was very competitive. My senior always completing resources in a destructive way. And my supervisor was claimed that he need medical treatment and so he go back to his home country for that. He only be in the University for four months during my Mphil study. After one year later, I was forced to quit my study because I have poor relationships with my supervisor due to my poor interpersonal relationship skill. And I was told my Mphil supervisor was kind of strange since he have some illness. Later on, I Applied for a MSc program and got admitted. But I was in severe depression and I hate all the professor due to what happen previously. I was nearly being insane then. I cannot afford to keep good relationship with my MSc supervisor due to my mental status. And I am now working as a clinical research assistant now which is totally not challenging. I still want to go back ti research field and get a PhD. Am I an failure? Am I qualified to do that? I am still on medical to treat depression.

Sorry to hear you feel that way. Another person might view the Clinical Research Assistant role a good position, whilst you potentially view it as a failure, so I think despite having challenges in the pursuit of a PhD, there is some faulty thinking at play here (we all have this to a degree).

I think the following book will help you. Particularly, the section on External vs Internal centred values.

https://web.csulb.edu/~tstevens/

or PDF version:
https://web.csulb.edu/~tstevens/ChooseToBeHappy.pdf

Wishing you all the best,
Jamie