In my personal experience, I am better off taking an evening dose even if I feel like I don't need it. I find that when I skip doses in the evening, the next day will not be as good. There is some buildup effect over time as well as you adjust.
From your initial post, you seem to be on a high dose for someone that is just starting. If I am reading correctly you are titrating up to 1000 mg/day? That's a big dose. When I first started I ramped up over several months to 600 mg/day and found out the hard way that this was actually too high and causing some fluctuations (took almost a year to realize that). I added entacapone and reduced to 300 mg/day and am much better now.
Everyone is different but I would recommend asking your neuro about dose schedule and if what you are currently on is too high. It is possible that the rapid titration to a high dose was for diagnostic purposes and not intended as long term therapy. (Some people are resistant to the lower doses, so some docs like to push the dose to make sure they aren't missing a benefit, for those patients that don't initially respond. It sounds like your response is not so much in question at this point though). The usual starting dose is 300 mg / day.
The transition to your potential new reality may be hard but just remember that PD and happiness are not mutually exclusive. Many people are scared by the idea of a progressive disease, myself included, but progressive symptoms don't need to result in progressive unhappiness. Stay positive and enjoy the benefit that getting your meds dialed in can offer.