Myself, I try to read at least 2 chapters a day. In the book I'm currently reading, chapters are about 10 pages, so I'm usually reading 4 or 5 a day. I think a number of chapters makes more sense than a number of pages, but chapter length can vary quite a lot, so I think it would help to be flexible with your goal. Be willing to change it on a book to book basis.

In my opinion - it's better to set a low goal - one that is attainable. No point beating yourself up for failing to meet unattainable goals you've set for yourself. Set a realistic goal, and if you read more than that on some days, great.

Totally agree. It took me a while to convince myself that it was OK to 'DNF' a book. There's just that expectation that you have to finish every book - and I say, that's not true at all. If it's not holding your interest, put it down and pick up something else.

Try a different book. Reading shouldn't be 'work'. If it is, skip that book. There are more books published than you can read in your lifetime - don't waste time on books that you don't like.