again and again

I've been feeling horrible for the past week or two. I've been trying to solve it on my own, like always but no luck. It's gotten bad to the point that I even got panic attacks from it, headaches, skipped some meals, etc..
I myself know how I should not think, however I can't fix it.
There's no external reason this time, I just hate myself again for being myself, basically.. and for pushing everyone away, voluntarily or not.
Despite what I say or do, I don't have any real problems, or at least, they are all caused by myself and myself only.
They say everybody's got ups and downs.. and that's true.. but I can't seem to be able to overcome my "downs" in a normal way.
I hate everything about myself.. some things I had managed to change, but overall nothing is changed. If anything I only blame myself over and over again for acting like this.
I will probably get back to normal sooner or later, but I've already been wasting precious days in this period of time in which I have much to do, especially university related.
And yes, I've been ******* my life continuously, been going on for years. I don't know what the heck is wrong with me.. and if the answer is nothing, why on earth I always get like this..
What am I writing this for? To be honest I have no idea.

I've sometimes been feeling awful for no particular reason.

When that happens, I try to do three things for myself. Eat healthy. Get some exercise. Get more sleep. It's worth a try imo.

You may have a low self-esteem, because when having a low self-esteem, you always find more and more reasons to hate yourself and dislike this or that. It's only your mind saying those nasty things and your thoughts aren't the whole truth. So yes, you're not as horrible as you think you are. It seems like you have gone into this endless cycle of negative thoughts and the longer it happens, the harder is to get out of that dark gloomy pit. The saddest thing is, though, you can only do that and no one else.