I sing in a band and my range is from G2-A4/B4 in chest voice and C5-G#5 i most of the time do rock Vocals but sometimes softer songs as well but im just wondering how to hold the falsetto notes on for a long time without straining. Any Suggestions are Appriciated.

My speaking voice is low but my singing voice is high so its a little weird and i cant figure how to get those high pitched notes.