Googley, looking at your post I see

• someone who has constantly worked hard
• someone applying for advanced studies.

These are not failure markers. I also see

• someone highly frustrated by immediate circumstances and very unhappy about it.

For you, I am less concerned about failure than I am about you being successful at something that makes you unhappy, or succeeding in a field that constantly throws up challenges undermining your happiness.

If you are certain you are pursuing a worthy goal, one that genuinely supports your happiness, then I would do my best to put aside fears of failure and mobilize your considerable demonstrated talents and go full speed ahead.

Wishing you happiness, now and in the future