Prescribed daily modafinil for chronic fatigue - how to prevent tolerance?

I've been dealing with chronic fatigue for 20+ years, and it's gotten worse recently, including frequent fatigue crashes where I'll have very little energy for weeks on end. This includes difficulty focusing on complex tasks for work or personal life. Instead of just trying to live with it like I have in the past, I've been making doctors appointments to find a possible diagnoses and see if there is anything that works.

Last month, I was referred to a physiatrist, who had me try modafinil. This is my first experience with any type of stimulant - I've taken phsyc meds in the past that did nothing for my energy levels, but just messed me up mentally, so I was a bit dubious about trying another medication.

I was put on 200 mg of modafinil daily, taken all at once in the morning. And... The results were actually pretty promising! I did feel a little wired and had a slight headache the first week, but that mostly ebbed away by the second, and I just felt some degree of increased energy and motivation. Not hugely life changing, but it feel like an improvement. It's literally the first drug that I've tried that's made ANY difference, so I was really hoping it would continue that way.

But by the third week, the effect had started feeling much more subdued. And now I'm at the end of the 4th week, and honestly, it's not really doing much anymore. I feel a VERY slight stimulation for about 4 hours in the middle of the day, but I'm back to having my standard mid-day energy crashes where I NEED a nap to continue operating, and it's very hard to focus on tasks without brain fog setting in. I feel like I've already built up a tolerance to the point where it just has no effect anymore.

I have a follow-up appointment with my doctor in 2 more weeks (6 weeks into taking modafinil) to see how it's going and whether we should change anything, and I was initially thinking I should ask him to increase the dosage, but after doing some research here and elsewhere online, I'm not entirely sure that's the right call. I know my situation is a bit unique since I'm not taking it sparingly for specific bursts of energy, but instead daily to increase my overall energy, but I was hoping some people who have more expertise here can help. Here's my specific questions, although any input not covered by these is great:

• Was 200 mg too large of a starting dose? I see a lot of people start with 50 or 100 mg, or space it more out throughout the day. (I take all 200 mg at 7 in the morning, as I found if I take it later it interferes with my sleep, but I haven't tried spacing it out yet.)
• Would upping it to, say, 400 mg be too much? I'm worried I'll overdo it, or maybe just accelerate the tolerance. (And I don't want to appear to the doctor that I'm just seeking drug-seeking by pushing that.)
• I see a lot of people talk about cycling, i.e. some days on, some days off. If that's an option, what sort of schedule would you recommend? Would just 1 or 2 days a week off be enough, or do I need to go for longer? Do the days off need to be consecutive to have the desired effect?

For now, I'm thinking about taking at least 3 days off to see how that effects me, but I want to hear other people's opinions on this first instead of just going off what info I found googling, as those may or may not apply to my situation.