How to tell my partner I have an eating disorder?

[Aceso]

I haven't been with my boyfriend long, but I trust him. I know he'll be fine with it, and he'll be supportive, so I don't even know why I can't open up to him about this, of all things.
It's getting bad. My dad's walked in on me purging twice recently and it's severely affecting my health.
I'm spending disgusting amounts of money every week on foods to just chew and spit.

I just can't stand the idea of being weak, of letting him down. He's my best friend, the only sense of true security I can recall having. I'm worried he'll be hurt or confused I didn't tell him from the start, or be disappointed I felt I couldn't tell him.

I'm just so sick of myself. I'm sick of nothing changing, and I'm sick of hurting those I care about.
How do I tell him? And how do I begin to help myself with this?
Thanks

[sam16]

Just tell him straightforward, if he loves he is gonna surely understand..

[BookSmart]

I know it's hard talking to people you love about this type of subject, but I'd go with the suggestion above: be straightforward.
Tell him there's something serious you want to talk to him about. Make sure that you tell him at an appropriate time; of you can't seem to find one, then try putting aside some time with him later on.

If you don't feel comfortable telling him in person, then you could always write a letter to him.

It's a scary thing to do, but trust me you'll feel a million times better after telling him about it.

[Ben_Frost]

Maybe it would help more if you told him about this issue but at the same time, reassure him you're doing as best as you can to get over this disorder. Maybe he would be willing to help you stop doing that to your body, if he truly loves you he will care and seek to help you out.

[Uranus]

I believe the best way to tell him is well....tell him. If he truly cares and loves you he will be ok. My gf had some things that she wanted to tell me but didn't know how. But she did. If you say you know he will be supportive and will understand, I don't see why you can't tell him.