What should do the get a job at a tech firm after this upset?

I interviewed onsite a few weeks ago. I studied cracking the coding interview, elements of programming interviews and geeksforgeeks for four months but no luck. I also got rejected by a few other companies.I’m so discouraged.. Recruiter said the HC said I had trouble translating ideas into code; I wrote some incomplete code because I ran out of time . Like for example , I had a DP problem, I wrote the recursive solution but didn't have time to completely convert it to DP but I explained how I'd do it. So much energy has been exerted but I stuck doing my same old boring developer job at Wall Street. I was really hoping to break into tech. I'd love to get into the big 4 ,particularly Google.