Each and every time you attacked* you went the same way, with all your troops, bashing your head against a brick wall.
I don't know what game you watched but the ISG was destroying him, why you didnt use its barrage ability, attack from 2+ sides with one side featuring a tank in beyond me.
*The best attempt you had, you wasted, you flanked him with 3 squads of volks at his cutoff and attacked the north with the rest of your army. You were too busy microing the army at the cut off that you simply stopped attacking with the north army and were forced to retreat.
After this you sent you volk INTO his main army, that's 3 volks Vs 2 MG's a mortar carriage, Sherman and 4+ squads of infantry, you lost them all as a result.
You should have captured his cut off and VP, leaving 1 squad in the house forcing him to split his forces to attack you, at which point you attack from the north with your new Panther and remaining army. That's when you lost the game IMO.
Off topic, look at this!
http://steamcommunity.com/sharedfiles/filedetails/?id=496654293
Something tells me the MG grouping needs a bit of a fix...