I think considering you started biking 1.5 months ago you are off to a great start! I think many people in your position would be unable to complete a 33KM trip, especially considering your practice is overwhelmingly city biking.

I of course am unaware of your previous physical shape, but assuming your body has not been trained to bike it will take you a while to get into shape.

My average is around 20-25km/h not including traffic stopping etc. It took me over three years to get here by biking to work daily, which is half uphill and half downhill (so I always have to bike uphill somewhat) and whenever I started feeling comfortable with my speed, pushing harder until uncomfortable again.

Some tips I learned in this experience and some I got from others:

1. Your muscles will get good and more efficient the more you use them. To avoid becoming complacent in your speed in the city for instance, consider every opportunity to push yourself.

2. Never going to make that green light anyway? Not today, try to make it as if your life depends on it. If you don't and have to break hard (you won't at first) remember you did it to be able to do it in a year if bot today.

3. Similarly racing plublic transport (where safe) can be fun as well as good training.

4. Isn't it nice biking in the wind shadow of this e-bike? Fuck e-bikes(cheaters(JK)), try to always pass them (great interval training) (the slow ones anyway, in my city some are capped at 20kmh and go more like 15)

5. Nutrition: I noticed after a year or so that certain breakfast items made it easier or harder to push myself biking

6. I don't know if you are EU or NA, but if EU or similar consider biking places that are relatively nearby, but you usually drive. This way you get new experience and slightly longer trips than you are used too which always 'stretches' you a bit more, then you 'snap back into place' a bit better that where you started.