Make sure you’re sitting up straight on the seat, too. If you’re bent too far forwards then you have extra weight pulling you forward, and you have to compensate by pedalling faster; which results in a upd. Try leaning a bit further backward. You’ll find that if you are seated properly, and focused on a static point (maybe a lamp in the distance), you will be more steadily balanced and able to pedal forward without much difficulty.
Everything became much easier once I started focusing on distant objects.
Remember to keep your head up - look where you want to go.