Letters to the past

Ever since i was 13, I have been writing letters to my future self; or rather, my past self has been wrting letters to me and our future selves.
I am 23 and i just opened a letter from my 13 year old self that was marked on the envelope “DO NOT OPEN UNTIL BIRTHDAY 2000.”
She told me a lot about herself and asked me a number of questions.
I have also opened letters from my 18-year old self and 21 year old self.
My 21 year old self received a letter from my 18 year old self as well.
My 20-year old self got a letter from my 16 year old self.
There are also letters addressed to my 40-year old self, my 30 year old self, my 62 year old self- you get the idea.
I have them all in a binder, but I can’t read the ones that are not addressed to me.
Anyway, I always write back.
I answered a few of my 13-year old self’s questions, but I didn’t say anything too specific for fear of upsetting the space-time continuum. I just wanted to give her hope. I thought that wouldn’t alter the universe TOO drastically if my 13 year-old self had a better outlook.
My problem is, I don’t know how to mail these letters to my past selves.
When I respond to a past self’s letter, I end up just putting it in my binder alongside the first letter.
I told my roommate I was saving them in case someday I figure out how to send a letter to the past.
He said that if i ever do figure out a way to do that, then I would have had the letter from my 23 year old self since I was 13. It would already have been written.
Also, right now i should have letters from my 62 year old self, my 30 year old self, and my 40 year old self and all the other me’s of teh future.
Is he right?
If not, can anyone still help me find a way to send all these letters backward through time?

Well, I think if it were possible to send letters back through time, you would have already received one, but who knows? So, I can’t help you there, but I can do something almost as good. If you want, you can tell me whatever your response was, and then it’ll be almost like your changing 13 year old you, except it’s 13 year old me. Would that work? Well, I hope I could help…feel free to email a letter to the past to sin1nombre@hotmail.com or, if you want to keep up that whole letter thing, email me and I can give you a home address…