I've been riding around 30 years and sometimes, 50 miles seems easy and sometimes 2 miles is impossible. Every ride is a new experience. The fact you are trying is something to be proud of. Just like walking and putting one foot out at a time, it's each pedal stroke closer to a goal. Don't get discouraged and award yourself each time you put on your helmet. Trust me we have all been there and done that. It does get easier and it should always be fun!