Look for an Ashran group in group finder and you will be able to cap. Takes a very long time and it's insanely boring but it works.
Got 12k conquest that way last week.
Do ashran long enough to get honor gear, or do random bgs. When you are at least fully geared you can try and find a partner in the groupfinder to do 2s with. Look for people who dont have a gear requirement, or start your own group. 1 win is 180 CP, thats equivalent to 1.8 event wins. Assuming you win every single event in ashran, you will get 400 conquest points every 43 minutes. without counting rares which are only 25 cp, its way faster to struggle through low rated arenas to get some points assuming you can win 3 times in 43 minutes.
Ashran is very slow. You get 100 CP/event and events pop like 5-10 min even if your faction is owning the events. Still it's the only option besides arena, as bgs are even slower than Ashran when it comes to CP farm cause you can actually lose bgs and waste your time.