Do I need a BO as Zerg?

Yesterday I spend my day playing...
costumgames against Diamand and Master Terrans / Protoss and their attacks reached my base so insanely fast. I struggled with a real buildorder to follow. As Zerg I usually played 15 Hatch 16 Pool 15 Gas against Terran but I had no real follow up except for me improvising. I overdroned without knowing what my opponend would be doing, I used to tech way too hard on 2 base (quadgase lair + warren + doubleupgrades) and I normally had a lack of T2 I used to forget about it pretty darn often... 
Normally I used many different strategies in the ladder but they were all improvable and not executed as well as they could have. (of course it's nice to have the occasional cheese prepared to screw a greedy oppnent of but you don't improve through 14gas 14pool mass Zergling or 6Pool)
So now I am trying out a different approach: (I actually hate monotony, that's why I played such unpredictable builds on the ladder [SUNKENRUSH *trololol*], that's why I have not tried this way of training.)
1. Finding a proper build for each matchup combined with a solid lategame plan.
2. Going on the ladder, playing those builds over and over again and prefection them
3. Watching / Uploading the replays and reacting on the individual possibilities that could occur
for EXP. the ability to protect myself against a bunkerrush / 2 Gate / Voidrays / DTs / Hellions etc. I have to be able to defent everything with the build!
4. The most important fact! I have to feel COMFTABLE with it. If it doesnt fit my style (I play somekind of a clear style - I don't like playing bit Roach some Lings Infestor that's why I don't like Stephano's playstyle)
I'll write the tactics I am going to use in my next post so stay tuned
~gghf