On the basis of those pictures I don't see a problem. The ratlines look fine; the ratio between their and the shrouds' diameters is about right. (I assume you're planning to paint the deadeyes black, and add the sheer poles.)
Maybe it would help to set up a schedule for yourself. I've found that a repetitive job like this gets easier IF I make myself stick at it for a while - say, a couple of hours. (Good music or audio books can help. I have a small stereo system in the workshop; I find that listening to a good story by Joseph Conrad or Herman Melville makes this sort of thing go a lot quicker.) The finger muscles will train themselves to tie those knots faster, but only if they get a chance. You might want to tell them they're stuck rigging ratlines for two hours - but promise them they'll get a break at the end of that time.
Another point: thread ratlines simply aren't going to sag between the shrouds the way you'd probably like them to do. Gravity doesn't function according to scale; it treats thin thread differently than full-size rope. Thread isn't heavy enough to droop like scale rope. The modeler is faced with a trade-off. Scale thread won't droop; wire can be shaped into the appropriate sag, but some people think it's not a good trade on such a large scale because the wire doesn't look like rope. The ratlines in those pictures look just as good as plenty of excellent models built by veteran modelers. My suggestion is: it's more than good enough. Stick with it.
Youth, talent, hard work, and enthusiasm are no match for old age and treachery.