I always beat France within the first few years of the game. (Maintaining a standing army of 20-25k troops)
Seems you are approaching it in a wrong way if you build 60k trops (you don't have forcelimit for that....), and your troops will be severely hit by attrition.
This is how you should play the game:
*Assuming you start with conquest of Ireland mission*
Day 1, you declare on Ulster, Leinster, Munster and whatever the last irish nation is called, you also declare on France (Don't call on Portugal yet). (You also build so you have a total of 25 000 troops, 20 000 infantry and 5000 cavalry)
(Also mint so you can buy defender of the faith)
You send your troops over to Ireland and easily defeat the irish minors and annex them. You should also build 3 cogs to get cogs up to 15 (how did you get naval forcelimit for those other cogs?)
Anyway, while doing all this have your fleet protect your coast, also keep Munster from sending troops to Aquitaine, keep like 4 carracks in their waters.
Now you get a new mission, I usually get vassalize Scotland or Occupy Paris. (If you get any other cancel)
It doesn't matter which one you get first, but Scotland is usually allied with Burgundy here.
If you get Scotland mission first, you declare war on Scotland and only concentrate on grabbing the 3 bottom provs, keep half your army in the western bottom prov, 1 regiment in the eastern and other half in the province above (keep 1 regiment loose in the western bottom as well if you would need to defend the top).
Once 2-3 of these provinces are occupied you can force vassalize Scotland (mission completed)
Try to get peace with whomever Scotland was allied with, and concentrate on the remaining threat (France), if Scotland was brought into the war by France, you might want to force vassalize them then instead, would make things easier
Now you should try getting Occupy Paris, get military access from Burgundy, and get 17k troops in Calais, and have 8k troops in the province next to it. When you are ready to attack, bring 15k troops into Paris, and keep 10k in reserve if it should lead to battle.
If you can here you should destroy the main french army, also call on Scotland and Portugal to join in your war.
Your main goal of this war (after occupy paris is finished) is not to take provinces, but to make France release nations. For example, in the first peace, make them release Normandy, Champagne and perhaps cancel vassal of Alenqon, Orleannais etc. If France haven't brought in all the vassals you got cores on into the war, you can also attack these and annex them.
Anyway, once these nations are released (weaklings compared to you), you can attack them and annex them.
Your goal should be to retake all your cores here, once France is divided, it's no longer a serious threat to you.
While doing all this you should add the HRE nations to your SOI, (to be able to offer vassalization in the future...very effective)
Once your main missions are finished, you will get generic missions, most of these is stuff like vassalizing Brittany and many nations much smaller than you, very effective CBs that give infamy reduction even.
You could also use your holy war CB from defender of the faith and go on a crusade.
EDIT: Examples of generic missions I got in my last game was force vassalization of Brittany (earlier game I got core missions on some of their provs), I got a conquer Zeeland missions (after shutting down force-vassalize Holland lol)
I got force-vassalize missions on Brabant, Navarre, most western minors (didn't play this game very far)
EDIT2: Also when you are done enact Staple Port decision in Calais and build a CoT there. Likey likey (like instant 1000-ducat CoT if you own most your cores in France)
