What is your option? When things don't go as smoothly as you had hoped, don't let emotions take over. Always ask yourself "What are my options?", because there are always options. For example, perhaps the lender takes longer than agreed upon to get your loan. He keeps asking you for more and more documentation until if feels like he also needs to know how many gold fillings you have in your mouth! You'll feel upset because you wanted to feel certain about the move and instead, you continue to deal with the uncertainty. You want to say, "Forget it, I'm fed up with this!" But what are your options? Find a new lender and start the process over again? That may take weeks, plus you will have to provide all the paperwork over again. If the lender is trying his best, it may be better to give him a few more days. Ask the lender why they keep asking for more and more stuff, ask him or her why they need more stuff and ask them if you're still going to get that commitment letter you need. Don't be afraid to ask questions - the only stupid question is the one you don't ask!! It's ok to ask people why they are doing things and why do they need things. If you understand the process, perhaps the next time you buy a house it'll be much easier for you.
Each case is unique, but when setbacks occur, asking yourself this question helps to defuse the situation and restore clear headed thinking.