Pop icon Cher is struggling with rehearsals for her upcoming tour and fears she might not be able to pull off such a "complicated" stage show.

The Believe singer's upcoming Dressed To Kill tour is said to be her last ever and Cher fears she is too old for the elaborate stage show that has been created.

The 67 year old has been battling insecurities during rehearsals and she shared her fears with fans just days before the shows kick off in Phoenix, Arizona on Saturday (22Mar14).

She writes, "On way 2 (to) rehearsal. So fkng (f**king) complicated. Why can't I just sing! I started the whole 'extravaganza show' (in) '79. Every1 (sic) made fun of me!"

She later added, "Just left rehearsal. Came home 2 (to) do homework! I hope you remember that u (you) love me when I fk (f**k) up!... Aching all over! Just remember you wanted me, and... I'm... almost 94!!!!!!"

She finally wrote, "I have turned imperfection & insecurity in2 (into) an art form!"