How do I stop myself getting messed up again?

I don’t know how to write about this really so I’m sorry if I sound like I’m wallowing in it, that’s kinda what I’m trying to stop… =)

For the past months I’ve felt so much beauty and love for things like I’ve never done before and it was like I found the missing parts of me that I was too blind to see ever before. It was kind of awesome, I’ve never known peace like that before…
But very recently, like the past 1–2 weeks or few days, there are things there that I forgot I felt before that keep coming back. It is like sometimes I can feel myself crawling all over myself and I want to tear it all off. And I can feel people’s eyes making me feel so dirty and disgusting because of what they see of me, it makes me so ashamed.
And if I am honest I did the self harm type thing the whole time, although before this started again it was not so negative (if you get me). There were massive gaps in between and I don’t especially understand why, but whatever the reason, there was none of this stupid sadistic and hatefulness to anything.

So how do you manage to stay above that when it tries to come back? I feel very guilty when really I know all of the beauty there is that I know can surround you, so if you can tell me how I can try not to get stuck….. =/