I don't want my advice to be overlooked because of my age

So I recently downloaded this app called Sincerely, and you write letters and other users write back and give comfort, advice, etc. but last night I got this letter to respond to and this person said that this was going to be their last letter and basically talking about how she's going to commit.

And I wrote back really quickly and I left my phone number which I admit probably isn't the best idea to give to a stranger, but if I can help someone, I'd want to. And I told her that if she's still there (the letter was from the day before) to call me. And whatever she wanted to talk about I'd listen, and I could give her advice, and it wouldn't be the most amazing or anything, but I'd listen. And she sent me text last night, she said she's alive and she thanked me. And this app it's anonymous, and it is supposed to be 18 and up on it.... And I may or may be under 18. But I still want to think that I give decent advice, and I don't want her to ask how I am because I mention something from my life or she can just tell by how I text, but I don't want her to not take my advice into consideration Because I'm 15, she has a job, and she's going to message at 2pm today, on her break.

And I'm really nervous, because I don't want to screw anything up. Or not be taken seriously, because I'm quite passionate in being empathetic and trying people.

This is the message I left

"I hope this isn't to late, but I just want you to know that life seems really hard right now, but can you tell me with 100% certainty and I mean 100% guarantee that you'll feel the exact same tomorrow? You can't, and what if tomorrow is a great and amazing day? I'd hope you want to be there to experience it. And I really hope that you're still alive and can read this, and I'm so so sorry you are feeling this way. And I really hope that you can take my words into consideration, and try a little longer on yourself. And I want you to know that I'm sorry, so so sorry that you've had to experience this pain, and I really want you to consider just this one question, "will it be like this 5 years from now?" Because life even though it seems horrible sometimes, it can be such a beautiful thing. And I just hope that if I reached you in time that you'll just second guess yourself this time. And I just hope that if I reached you in time that you'll just second guess yourself this time. And I want you to know that despite what you're probably thinking, it won't feel this way forever. And I don't know if this is allowed on the tos for this app but if you're still alive, I want you to call me, just rant to me about why life sucks, and I can't guarantee that I'll have the most amazing fantastical advice, but I want you to know that I'll listen. And I've been through a lot in my life, and I've debated commiting, many times, and I'm so glad I haven't. Because if I did I would have never met and experienced things I have now. Seriously. Please call me. And If I can't pickup, leave a message and I'll call you back as soon as I can."

I've been told I'm a grandma in the body of a teenager 💔