It's gone orange... Can this be washed out?

Purple direct dyes either go green or pink when bleached. I think Purple haze goes pink, so the orange tones that you are seeing are probably from the remaining purple dye over your yellow base.
So a few shampoos should get it out, dandruff or clarifying shampoo is best. A sulphate based purple shampoo such as Touch of Silver is also pretty good at stripping out dye and adding cool tones.
A blue based purple, rather than a pink based one is best for toning brassy hair.

Thank you! I'll go out and get that Touch of Silver you mentioned, as well as some dandruff shampoo. Would it be okay to get Olaplex before I have it faded out, or would it 'seal' the color in?

Olaplex doesn't leave any residue on the hair, it isn't a conditioning product. It won't affect the colour at all

Sorry for the bother, one more question... So I'm planning on using the T18 Wella toner (will strand test first) to bring my hair closer to white, but is it better to do this before or after Olaplex?

I don't know anything about this stuff, but my thinking is if I tone before olaplex, the cuticles are already lifted and then ola will smooth out the damage afterwards. But if I do ola first, then my cuticles would be smoother and less likely to come out unevenly (since the bottom half of my hair is more damaged than the top).

Any advice on this front? And again, thank you SO MUCH for your help. (<3<3)

You can put it in the toner. If your hair isn't a very pale yellow though, it's not going to do anything much so it's not really worth it.

And peroxide that you put in the toner will lift the cuticle regardless of using Olapex or not.

Hmm, well it is quite pale IMO. I'm mostly trying to get those red/pink pigments out. I actually really liked the weird slightly green blonde I had before. Fingers crossed that the T18 will do that (remove the red).

Most likely it won't. It's not made to remove pigment, so it's just luck if it does. It's also only going to tone the yellow, it won't tone the pink or red.

If your hair is still the same colour as the last photo, it's too dark for t18 to do anything.

Okay. I'm going to try the T14 tomorrow then.

The same applies for T14. A blonde/white toner isn't going to do what you want it to do.

Okaaayyyy...so. Purple shampoos and conditioners are my only option?

At least they won't add damage like the toners will. The pay off for damage ratio is far more acceptable with the Touch of Silver shampoo. There's also clarifying and dandruff shampoos. They just won't add the cool tone.

Sorry for the bother, one more question... So I'm planning on using the T18 Wella toner (will strand test first) to bring my hair closer to white, but is it better to do this before or after Olaplex?

I don't know anything about this stuff, but my thinking is if I tone before olaplex, the cuticles are already lifted and then ola will smooth out the damage afterwards. But if I do ola first, then my cuticles would be smoother and less likely to come out unevenly (since the bottom half of my hair is more damaged than the top).

Any advice on this front? And again, thank you SO MUCH for your help. (<3<3)

This is not how Olaplex works, it is not a conditioner. It has no effect on the cuticles it only links broken disulphide bonds which are part of the inner structure.
If you use an oxidative toner definitely add the olaplex, but I agree with Janine, it will cause too much damage for the amount of toning you get. Those toners contain high levels of ammonia which is extremely damaging on bleached hair, and they are designed to be used on light blonde hair only.