Should I spend the other half of my life believing God to heal my messed up life?

I tried fixing myself to change to do what the Bible says to do but all my years have been wasted still at point A. I have reached out to God for over 25 years of my life and He only left me disappointed, I don't need anymore disappointments in my life seeing I have enough as it is. I want a God that moves in my situations, and that can move mountains, not a wimp! The more He lets me down, the more my mind is programed to believe He will not. I already know if I were to reach out to Him by faith to help me He will just disappoint me again like the billionth time He's done before!!