This will get buried but screw it.

Consistently pushing yourself to your limit is extremely myopic. Yes it will get you slightly faster results. Yes it is important to sometimes push yourself to overcome plateaus. But if it sucks to workout then you are literally conditioning yourself to hate working out. This is a recipe for giving up.

Your goal shouldn't be 6-pack by summer. Your goal should be to make fitness a consistent part of your lifestyle for the rest of your life. So if you really don't feel like working out for an hour then don't! Work out for 10 minutes instead. If you build the habit then you'll start to view it as something you want to do rather than something you have to endure.