Guild Wars 2

So I am super excited by the look of Chronomancer and as such have decided to make and level a mesmer. Problem is, I really struggle while roaming in open world and fighting groups of trash mobs. the reason for this is that all phantasms are castable on only one enemy and then die instantly after I kill it. As a result of this I struggle to take down trash mobs because 50% of dps comes form phantasms and they are almost constantly being lost. Im using a standard s/s/f build.
Can any pro mesmers give me some advice or a quick build on a better way to do map comp and leveling with a mesmer?

TL;RD plz give me a mesmer levelling guide/build

You can always try my leveling guide.

It’s in my signature.

Holy crap dude this is amazing, i love it very interesting read, and 120% informative