Bikes aint bikes..

Went for a bikeride this afternoon, first one in awhile though.  I have tried though, kinda.  Sometimes.  Once or twice anyway. 

A couple of months back I was going to start riding again and on the 6th September I did.  And a couple before that and a couple after, did some stepping too and was getting the numbers up.  But then I stopped.  As I do.  Then I went and stayed with a woman and she has a bike that she rides 3 times a day, every day.  So I asked if I could borrow her bike and go for a ride around the oval.  And I did.  That bike was so easy to ride I rode for miles, every day I was there.  Then I came home and rode my bike.  Not easy, so hard I couldn't get to neighbors driveway without hurting and being puffed.  So I came home and put the bike away.  Went to womans house again and rode her bike.  For miles, it was so easy.
Husband looked at my bike, fiddled with the gears, sprayed everything, pumped the tyres up and I rode up the road and around the corner.  Hard but doable.  Next time I tried, harder.  But I felt the tyres and they seemed OK.  He comes out and tries the tyres and pumps them up and I rode around the corner to the limestone.  And today to the corner and back. 
But I think I need another bike.  What sort and where from?  And how much will it cost me?!  No idea what I need and though I have looked at KMart I am not sure if they will be any easier than the one I have now.  I may need a visit to Mandurah or Bunbury and go into a proper bike shop for advice.  In the meantime I will ride mine when I can.