In my opinion, one of the main reasons for people giving up
This is not really a required discussion point. It unnecessarily lengthens the discussion by veering off-topic. You should always stay focused on the actual discussion target. Rather,,start the paragraph for scoring reasons at:
it is worth it to keep trying
You don't need to keep saying that this is your opinion because the prompt has made that clear. So start at the topic sentence instead. The discussion relevant part.
But
Try to avoid using a conjunction to start the sentence. That is academically incorrect as the conjuction is used to connect 2 apposite ideas in one sentence.
So to conclude
This is not an IELTS test. A conclusion is not needed. You don't have to use this phrase. Instead, use a simple closing sentence to wrap the discussion. Just close. No need to summarize either.