How do you make time for trains?

[faraway]

.... It feels almost as if I've taken a step back ....

Not at all. You are doing huge steps in your education, profession, partnership and may be soon as a father. You are doing very well and you adjusted the balance because you learned what real life is and what a hobby is. Absolut no reason to worry.
ps. Retirement is the right time to rethink the priorities again