Ok, I am starting to not enjoy this exercises. I am averaging only two problems per day. Pawn structures are not the only ones being anihillated right now. My confidence is shot to pieces. Very rarely do I get the whole sequence correct. Sometimes I would get two, maybe three moves if I'm lucky. But I have not once gotten the whole variation. We can say that getting the first three moves is a good thing. And if this were CTART, I may get a few points for that. But sacrificing material forces you to be very accurate. If mate, or huge material compensation was not achieved quickly, you die. So in a real game, I am never going to have the confidence to initiate such long forcing manuevers without seeing up to mate. And I am blind. I tell you, blind!!!
Which brings me:
Maybe I should just try to solve within ten minutes and then go look at the solution? But I am using the tactical exercises to train my thinking process too. I mean, in a real game, there is no solution page to turn to. And so I try to work out all the variations as if I'm in a game. It's just is taking too much time.
In your place, I'd definitely give up after 10 minutes and look up the solution. In my opinion, 10 minutes is more than enought to spend on a position. Next time you see it, you'll get it right.And after literally burning the patterns into your mind, your calculation ability will most likely improve as you'll have a lot of familiar positions to fall back to.And they say the mind is much better at pattern matching than calculating, too :)