If you are not taking the p1ss, you could not be going about this more badly if you tried.
Stop worrying about gear ratios and average speeds, and contrary to what TNT suggested, I don't even think you need a structured training program or a coach at this stage.
Just ride your bicycle. Do so regularly, mostly slowly and go further before you try and go faster.
When you find that your weekly ride around the cradle is becoming easier, and you can do two laps without struggling, get a coach and get faster.
Your current approach, if you are not taking the p1ss, is just plain pointless.