Conclusion

The Manhattan Project did in fact achieve its goal or ideal, which was to build the first atomic bomb and end the war. It also provided the world with an alternate energy source which is nuclear power, which is basically controlled nuclear fission which takes place in nuclear reactors.
Unfortunately the consequences of it were a tremendous death toll and a new great threat of extinction. The atomic bomb was so powerful that extra security was needed due to paranoia, eventually it led to an arms race between the U.S. and the Soviets known as the Cold War.

So was it worth it or not necessary at all, or how long would it taken till another country built an atomic bomb and take control?

Check out the bibliography to see the sources I used.