Assuming this is accurate on the total network hashing power...

https://btc.com/stats/diff

On 1/10/2017 it was 2.41 Eh/s
On 1/13/2018 it was 15.95 Eh/s (562% gain)
On 1/24/2018 it was 18.63 Eh/s (17% gain in 11 days)

So my question being that I'm concerned how quickly my 40.5 Th/s will even be worth running. As pools grow profits are spread thinner and difficulty rises. Maybe someone who's been doing this longer than me could offer some insight? Truly just looking for some feedback but these numbers kind of startled me.

Edit: I'm not panicking, just looking for solid experience from those who've been doing this a lot longer than I have. I'm still pretty new to this (11/2017).