I'm going to end my suffering soon

I'm a 29 yo French man. I suffer from loneliness, a great lack of self-confidence and other things like alopecia that ruin my life.

A while back I met a girl by chance on Snapchat. She was in my suggestions, I don't often add people I don't know, but I had added her. I don't know why, but I thought her nickname was cool. She added me back.
We quickly hit it off and I fell under its spell. She seemed to like me too.
The pity is that she lives on the other side of the world, literally, 14000km away in Australia. She's the most extraordinary girl I've ever met. Beautiful, simple, kind, affectionate, generous, intelligent, wonderful soul...

In fact, she'd never had a boyfriend before, and even if we weren't together, it was more than friendship. My goal was to make the journey to meet her in a few months' time. If I could have done it sooner, I would have, but a trip from Europe to Australia isn't cheap and you have to prepare for it (passport, visa, etc...).

A few days ago, what had to happen happened...

She told me she'd been hanging out with a boy she'd met very recently. He's very nice too and told her he'd like things to go seriously between them. The thing is, he's on the spot, I'm on the other side of the world.

She told me she'd give him a chance and that she'd prefer, out of respect for him, for us to stay there because she cares a lot about me and it wouldn't be appropriate. She assured me that life had worked out badly because if I'd been in Australia or she in France, we'd have been together without a doubt.

I accepted the situation and our goodbyes were terrible for me. I don't want to lose her, but I have no choice but to accept that she'll be happy without me.

My life is summed up in the blink-182 song “Story Of A Lonely Guy”. I haven't had many relationships in my life, and I've been through some very difficult things. I've been through some pretty dark times in my life, but life has just put me to death this time.

I'd found the woman of my life, I know it's weird to say, but she was my other half. I can't take it anymore and I can't go through another depression, I'm giving up...

I can't blame her, that's life and I wish her all the happiness in the world. She's been waiting to find the right person to stay with her for the rest of her life, and I hope she's found him. I hope that this boy will love her as much as she deserves and that he will never hurt her and will be there for her until the day he dies.

But as for me, I'm sinking like I've never sunk before. I'm empty, I've had enough this time.

I'm not here for advice on how to get better, that's over for me! I refuse to continue.

I'd just like to know if it would be selfish from me to send her one last message telling her I'm leaving for a better world, that's not her fault and will wait for him forever.

If she ever tries to contact me again, I don't want her to think I don't want to talk to her again when I've simply ended my life.

Should I tell her?

I'd so much like to have met her, taken her in my arms and kissed her at least once, but it's too late...

She's the most beautiful person I've ever met in my life and I can't accept that I've lost her so suddenly. I just want all this to stop but I don't know what to say to her, if I should say anything...

Please help me leaving this world in peace !!!