I keep having these really "quiet", intrusive thoughts that 'X' might cause me anxiety, which in itself then immediately causes my anxiety to shoot up for under a second, before leaving me to recover from it/calm down over the course of a couple seconds. 

It's a very intense feeling and it only began happening after I gave myself an MDMA-induced anxiety disorder, in which I got these spikes of anxiety in reaction to various, random things, which in turn caused me to fear them, in fear I'd receive more of these "anxiety spikes". I later found out these things that spiked my anxiety were unrelated and it was simply anxiety playing tricks on me but at that point it was too late as now I can't seem to stop myself feeling anxious in the presence of these things, which is what causes the quiet, intrusive thoughts, which cause my anxiety to spike.

Apolgoies if I repeat myself a lot. Please help!