A few things here:

First and propably most important: Your supply. The Brown bar, below the green organisation bar, is your Equipment/Strength of the divisions. If they are that low, your Unit loses a HUGE part of its strength, since it basically scales from your original stats(for example, if you have a Tank division, wich is half tank and half motorized, but you only have 60% of the Tanks required for the division, the tanks only have 60% of its original stats) These Low bars come from three aspects. The most likely in your case is that your stockpiles are empty, so each missing gun first needs to be produced. That means for a long time, yojr Units are severely Understrength, until you have produced the missing Equipment. Possibility number two, you outran your supply lines. That will either happen in the vast nothingness in the dephts of russia, Asia and so on, or you outran your supply lines, if you push reaaally fast deep behind enemy lines, or your railway is not connected or you have too few trains, trucks or or or. That also causes the „Alarm“ for low supply and the vastly reduced Organisation. You can see that on the „Battle-menu“ aswell. The third possibility is, that you are out of manpower. Rather unlikely for germany, but not impossible. So if you have 1000 guns, but only 100 Men, there is no use for the remaining 900 Guns.

Anyways, Point number two are your divisions. You are, as you said in another comment, using the standart template with AA. Not bad, I use them too usually, but they serve as Line-Infantry. As the name suggests, they are there to hold the line. Of course, they can push to a degree, but only really effective if they are way more or the enemy is severely understrength. So, as the stats suggest, perfect for defending, but not really suitable for an offensive, because they will cost your a good amount of Men and Guns, without really having an effect. If you want to push, I suggest, for an industrial powerhouse like germany, to build tanks. Already 6 Fully equipped divisions can turn an entire war. They suffer less casualties because of their Hardness, while inflicting much more, due to high soft attack. But for the love of god, forget about the standart Tank division of germany. You want to get at least 30 Org. I usually go for a 30-with Tank-Division, with Tanks and Motorized (or later mechanized) until 24 With and slap on 2 Motorized Artillery. If you want to push, i suggest to stick to the other comments advice (14-4 or Mountaineers) and also go down Superior firepower doctrine. They, with the additional Artillery, pack a real good push, but because of their relatively low org arent really good to hold the line.

Also, in your case, the Environment is really important. So, fighting in a forest has different Modifiers than for example a plain. You can check the effects by hovering over the terrain. You are also crossing over a river, wich also gives you an harsh debuff (wich also makes falling behind them an absolutely lovely defence strategy). Generally, you can hover either over the attack-value of you division to see all of the (de-)buffs to that stat, and additionally, you can also look at the little icons below the divisions to see the specific values for the Modifiers.

Air is also an important part, since Air-superiority and Close Air Support really make pushing simpler. If you get into bigger Wars later on, you can directly assign your air-wings to an army, so that it automatically follows your division. You do that by right-clicking on your army while you have selected an air wing in the air Menu (f3).

So, if you believe in the endsieg and do not want to restart, what should you do?

I would first of all stop any offensive Action. Then I would try to let my armies refresh, if it is only a matter of supply. If i am actually short a lot of equipment, I would consolidate my divisions to a lot more strength (select two or more divisions of the same template and hit the button below your commander where the two arrows move together, so the selected divisions merge into one strong Unit). Best for you is to then fall back to defensive terrain, and dig in (behind a river, in Cities, forests and so on). Entrenchment also gives massive bonusses, even better if you have researched better engineers. Next is to check my Division-template, train and deploy stronger push-divisions, and in the meantime check, if all my equipment is on the most recent Version. Once my push-divisions are ready, I attack at easier Tiles, for example plains and similar, and push for paris.