Not quite Alice through the .... but when I start folk off in calligraphy (or any new hand for that matter) we always work BIG. It doesn't necessarily feel natural but there's a method in this madness!
Working big (eg a size 0 down to 1.5 William Mitchell broad edge nib) is a bit like looking in one of those magnified make-up mirrors that show every blemish and pore! A tad scary to start off with but the idea is that all the flaws will be highlighted and these are so important to see if progress is to be made.
Working too small will disguise any areas that are not quite working - especially the relationship between thins and thicks, where oval shapes meet a down stroke, the neatness of a flag serif, the continuity of serifs and ligatures, the adherence to x-height and base line (more of that soon) - I could go on but you get the idea.
Working big also allows me to more easily guide the eye to the left and right side of the nib to help meet up with a committed stroke. I talk about "white or counter space" - training the eye to look at the white space the pen strokes are leaving and not just the actual pen stroke itself. It's all too tempting to start working with a smaller nib as this is more tempting for the pieces most folk will want to scribe as finished artwork.
Be patient - you'll get there and believe me it's worth it. When you've worked small for a while and go back to a big nib it's so satisfying to see it working- really working! Like all new skills - learn to walk before you run. Keep calm and keep practising your calligraphy!