I used to have problems with modded MC. Basically the only thing to do is the whole fresh install process. 3 Ways to Reinstall Minecraft - wikiHow
While you do that, make sure your computer is capable of handling soartax. I use that pack and it works fine on my laptop however you may fine getting a 16x16 pack is much safer. There are plenty of good packs for lower end computers ^-^
16×16 | Minecraft Texture Packs
As for hacked clients, Huzuni never fails me. Use 1.7.10 or lower and download from here. If you already have downloaded it, redownload it.
Minecraft 1.7.10 Hacked Client - Huzuni - WiZARDHAX.com
And it works with optifine so thats another bonus to improve your performance.
It has tracer so you should be all good.
good luck hun ^-^