What I noticed from your play is that you generally feed too much. Remember, units are like tools. If you apply wrong tool to problem, you can lose the tool and still have problem unsolved.
Primary advice: try to get best counter to your enemy's units. Consider facswitch if your fac is ill-suited for dealing with problem. Your goal should be low attrition ratio: force enemy to lose metal value while keeping your value intact. If you find yourself in a bad situation, consider temporary retreat.
Try not to suicide raiders to porc or arty. Commit to engagement only if you have good chances of winning, or having means to reclaim battle scraps later.