Why do I slide sideways on my homebuilt?

I know very little about iceboats. That being said, I decided to build my own. I bolted up two 2x6 planks in
the shape of a large T, affixed runners to the sides
of the top and a steerable runner at the base of the T.
OK... so the basics are there, right? Now I get a little strange. My seat is at the midpoint of the T and I face the top of the T. My sail is stolen from a Sunflower and is mounted at the intersection of the top and base planks. The runners are too short in comparison to those I've seen in pictures being only about 14"; they're made of 2x4 with 3/16 steel plates
that extend beyond the wooden bottom of the runners by about 1/4". Total weight of this rig ended up about 60 pounds.

This was the creation of much of my last Sunday. I spent a total of about $1 for bolts with all other materials being rounded up from my garage bins and boxes. The wood, as a matter of fact, was recycled from
some demolition near my work. Somewhere in the background someone is saying you get what you pay for.

My wife, a friend, and I took this rig over onto Lake Champlain today. I can't characterize ice at this point
other than to say there's a whole lot of it with very little snow out there. I have not seen any iceboats by Burlington and assume there's smoother ice somewhere
further up the lake. Wind was dying when we finally got
out on the ice which was around sunset. With 5 to 10 mph I could get the rig moving but the Sunflower sail
is basically a large letter A shape turned sideways and
the pull of the sail is off centered to the iceboat and
would repeatedly pull my whole boat sideways rather than having the blades control direction. I found that if I weighted the tail end (over the tiller/rudder blade) then I could control direction.

I definitely have to work on my steering linkage. The
handle is a slide mechanism reached below the hip. There's not a way of determining the neutral position with this set up. I flat filed the steel blades that are mounted on the runners. Do they need to be hollow ground like skate blades? The tiller/rudder mechanism
has a steel blade mounted on both sides. (picture an
inverted letter U. Again... the steel blades protrude only 1/4" below the wood.

I suspect I need to move my center of gravity aft to
put more weight on the rudder. My blades are basically
flat along their length with a rise over the last 2" to
the front. Possibly the blades need to be sharpened;
if so are they hollow ground, canted with the edge to
the outside, middle, or inside? Perhaps rather than
flat along they're length they need a very small bow?

Can someone recommend some suggestions or reading for me to gain more insight on this? I recall seeing a very
small tubular iceboat years ago but see nothing mentioned about them at the websites I visited.

I'm also curious as to the possibility of switching
over to a sailboard style sail but it looks like quite
a bit of rigging would be necessary to use one.

In any case this has been quite a bit of fun already
and something I'd wanted to try to do for years. It
seems that this will have been a great year for the sport and I hope all that read this have been able to
enjoy it. Champlain has been frozen over for going on its 4th week and its had several periods with little
snow obstructing the ice.

Regards,
Art G.