The human obsession with the universe coming from 'nothing' and then having a finite end is based entirely on our own linear perceptions of time where we see life, stars and everything in between having a beginning, middle and end. We therefore assume the universe must also be so.

And yet we also know that space/time is both non-linear and relative to the observer* and can be warped, for example by black holes. This puts that idea to bed.

We also know that energy cannot be created nor destroyed, only transformed from one form to another. If this is true then all the energy in the universe must always have existed, even as potential energy.

I would posit that the universe is actually self-perpetuating and it may be that our universal age is one of many. Eventually all the black holes collapse into each other, creating a super-dense singularity which then explodes outwards with all its pent-up energy and another universe takes form. This process has always been happening and never actually had a linear start. We struggle with this idea because we cannot process the idea due to linear existence.

*My laymans understanding is that time is relative. Someone travelling close to the speed of light experiences time differently to someone at a slower speed. The adult Mayfly with its 24-hour existence does not think 'oh man, I only live for 24 hours'. It thinks 'oh wow, those humans have infinite lifespans.' Eg: https://www.theguardian.com/science/2013/sep/16/time-passes-slowly-flies-study