I need help. But I can't go into too much detail, because it's secret. I won't even tell my best friends(and don't pester me, guys! School's hard enough!).

Pretend for a moment that you have a secret. A big one. You know you must tell someone(it's extremely important that you do), but that "someone" doesn't like you much, and you argue a lot. How would you go about telling them?

For example, should I get on their good side, blurt it and get it over with...what do I do?

And I need answers ASAP, because the secret is killing me the longer I have it. But I feel like it will kill me if I say...someone help!

That's not really specific enough for anyone to give you advice about, I think. Is this a life-threatening secret? What do you expect to happen after you tell this person, and do you think it's for the best given the situation? Do you feel there could be a better time and place to share the secret in the future, or is it urgent? Without knowing anything else, all I can suggest is that you ask yourself those questions and decide on your own. And sometimes the right decision is hard.

Okay, it's not endangering my life, or anyone else's. After I tell them, they'll probably just get really frustrated, but I don't want that because I know they're stressed enough around me.

If I tell them in the future, it'll have to be soon, about sometime before the next two or three weeks.

I know the right decision is hard. But making it is harder.

Ah, okay. I think I must have misunderstood you to be asking whether you should tell them, rather than how you should tell them. My bad.

If you can catch this person at a less-stressful time and take them aside privately, that might be best. You said this secret is likely to make them frustrated and stressed out, so is it possible that you could offer to make the situation less stressful in some way? This might not apply to you; again, I don't know. In the end, it might just come down to working up the courage to straight-up tell them, as you said. Since you know this person best, you'd likely have a better idea than anyone else. 

If this is a friend then just say it 

If this is a family member, knowing your family won't like you telling them later knowing you knew for a while. 

Either way just say it, they will get over it eventually and once it's out there. once this person knows they might be angry but the guilt will stop 

Whos stressed around you? 

Btw- I will not pester you about it