Losing

I have to say I am gutted. I play on here with very small stakes and don't mind getting it wrong. On the course I bet much bigger, and expect to win most days. This may be because over the last two  and a half years I've been racing on 80 occasions and only have 10 losing days- until this year. This year everything that could go wrong has. I've already been racing 14 times, and only had 5 winning days.
Things have gone well in the past, we (me and the mrs) narrow the field down on the form at home, and make a final decision at the pre parade ring, usually having a bet each in a field of 8 plus. The Mrs is a novice of 4 years, I've been betting since burrough hill lad won the gold cup. This season horses sweating themselves senseless and those dragging their knobs along the ground seem to be running out of there skins. Tonight at donny we had a winner, it should have put us in profit but, the mrs only had a quarter of my stake on it (6f sprint 18 runners) I had stupidly assumed we were betting with the same stakes. we had a similar mistake when La sarazine won at 16/1 a couple of months back over the jumps. I had backed the stable mate who ran like a pig, assuming she had backed it with the same stake- instead she had used a 1/8th stake. I'm thinking all we need to do is communicate better on course, but in all honesty I'm experiencing a serious lack of confidence, I think I'm always looking for the 20/1 winner rather than accepting that the most likely result may be a shorter odds winner.