So long as you hang in there and keep on keeping on you WILL make progress. Three weeks is not a long time. See where you are three months and then three years on down the road. Assuming you hang in there the differences will be amazing. I've been on the bike a bit over a year now and without getting specific, things that are routine now were not even thought of when I started riding.
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It's all downhill from here. Except the parts that are uphill.