2.5 years post surgery

i am 2.5 years post surgery  i lost 50 pounds and need to lose 50 more and just havent done it.   i feel like a failure and need to just go back and lose it.  i am starting today on the lose it app.   and walking daily.  i am mad at myself for not staying with it and losing it in the beginning.  has anyone else had the problem ?  please help with advise and stories so i know i can accomplish this.

I went back tomy surgical team and signed on for extended nutriTion and fitness guidance im determined to lose that last 40-50.