Two quotes here that make me think that you are being too hard on yourself, Toffidil, It is beaten into us at school that we “must make an effort”, or “we will fail”, and so, when we become engaged in something, and enjoy it for its own sake, we feel that we “must try harder”.
Let’s ask: Why do you want to be able to read Welsh? I would guess that the answer is probably something like “because I enjoy Welsh, and want to use it more”.
So, why take the enjoyment out of it by making yourself work harder?
There’s a fair amount of evidence to show that we remember things better when we have forgotten them and been reminded, and that stress blocks the process. So, why not try something like this:
Read an article, using the vocab button as required. Do something else. Then read the article again, using the vocab button as required, but pausing before each use for a second or two - no more - to see if the word springs to mind. If not, don;t beat yourself up - you are reading an article in a language that you are learning as an adult. That should be seen as a pretty big achievement, even (especially) if you don’t understand all the vocab. Celebrate it!
When you remind yourself of the word that you’d forgotten, it will lodge a little deeper in your memory.
If the article is about something that interests you, then feel free to read it again tomorrow - bookmark it, or keep it some other way. If it’s a subject taht you’re not really interested in, then don;t bother, because who cares about that particular vocab? Find something more interesting to read!
There’s a good choice of articles in Welsh now, through BBC Cymru Fyw and Golwg, which both have vocab buttons.
One final thought. Would it help if you could also hear the word? I’m certainly better off hearing as well as seeing a new word, as I am more confident about using it then, which makes me more likely to remember it.
If so, keep Ivona.com open at the same time as you are reading. When you find an unfamiliar word, put it into the text to speech box, and voila! You can hear it as well. You may like to listen to a word you cant remember before clikcking the vcab button sometimes, but not too often. The idea of reading the article is to enjoy it, not to spend hours reading a 100 word article about the latest craze for crawling through broken glass!