I Cant Change the Past But I Can Change My Future

I had been in a group that said I'd go back to the past if I could. I have reconsidered. It would make me too sad to see all the people who have died in my life and not be able to warn them. If I warned them it would change my present, in unimaginable ways. I loved my aunt, uncle, grandmother, boyfriend, grandfather and mother. So many more too friends and employees and colleagues. I would overload and it would send me right back into that vortex of death.
I know I can change my future by the choices I make in the present. That seems to be such a heavy burden though, you look forward and see like 8 trillion outcomes which choice can you make?
So to me it seems best to just live right now. This very second is all there is, past is gone, future is empty. Now matters most. I suppose if I make sure I make all my seconds matter, and live my life in each one, cumulatively they will build my better future, but I'd rather not focus on the macro.
Ok well that's my thoughts on this.