The best way to get over the phobia is to remember its just an awesome computer game you're playing. Take deep breaths, have fun and experiment
If you take heavy losses learn from your mistakes as best you can and make them pay the next time!
I have been using 3 battalions worth of Soviet mechanized infantry as part of a big tournament for a couple of years now. advice I can give is that mech inf work effectively as a springboard. As the soviets I preceed my mech units with scouts and engineers, and cover them with tanks. I keep them all bunched up in concealed positions. On the attack I sneak them closer and closer as undetectable as possible, like a coiled snake ready to strike. and when they are in striking range and one has suppressed the defender well enough (or the attacker in a counter attack situation) once unleashed they are an extremely effective means of overwhelming an enemy.