I can't glide without pushing off my topepick. Can someone give me advice on how to stop this, as well as how to glide for longer?
Yes. Bend your knees. It's the key to pretty much everything in skating.
There's a sequence to proper forward skating which, weirdly and very unfortunately, doesn't appear to be taught by many British coaches.
Feet in the T-position to start left foot pointing forwards, right foot at a 90 degree angle behind it.
Bend
both knees and push onto your first left forward outside edge glide, making sure you push from the inside edge of the right, pushing blade, with more pressure towards the rear of the skate and keeping the toe pick from hitting the ice.
Glide on the bent left leg with the right leg stretching out straight behind you after you push.
Gently rise up on the left leg to straight as you glide, with the right leg coming in till the right foot is alongside the left, but still off the ice.
Then - crucially - bend both knees while the right/free foot is still off the ice and change your left foot edge to an inside one as you skate. Both knees should still be bent and your feet side by side with the right one still off the ice.
You then start the sequence again, pushing from that left forward inside edge onto your right forward outside and carry on as above, stretching the left leg out behind you, etc...
It can take a long time to get this sequence in your head and is best practiced off ice to start with, holding on to the back of a chair or a kitchen counter as you talk yourself through it until it becomes second nature. Also practice it holding on ice but holding on to the barrier, before you try it as you skate.
Good luck!