Correct Score trading learning

So my first day trying to work out trading the correct score on Betfair rather than betting on Bet 365. I fancy Morocco to win 2-0 or 3-0 so have £15.00 on 2-0 and £20 on 3-0. Morocco score after 9 minutes and go 2-0 up after 27 minutes. I panic....should I be doing something ? I leave it figuring I have the 3-0. Zambia are awful, Morocco look like they could score 10. At fifty minutes, Morocco go 3-0 up. I'm being offered a small profit but am confused as to why it's so small and concerned that another goal will see me out of the game. Bear in mind this is all experimenting. So I back "Any other away Win" at 6/4 for £40. The game goes on with me expecting another goal any moment thinking at least I have that covered for £60 which will help and give me a small profit. However the offer I'm being shown is a small profit of £25.00 on the green. Panicking I cash out at 60 minutes which returns my stake of £35.00 plus the £40 and showing a profit of £25 on the transaction which I cash out at around 60 minutes. So today I'm wondering how I could have done better, especially given the match ended 3-0 and if I had stuck in would have shown a £140 return on the 3-0. I think I was too concerned on protecting my stake. If I had been on Bet365 and had a straight £20 on the score, I'd probably have let it run to the end........any advice would be welcome. Is this a typical newbie error having purely watched YouTube videos to understand trading?