I have been working at a conference this week and have met a lot of people that I haven't seen for a while. As part of the normal courtesies they ask "How are you and your family?" and I almost always answer "Fine" because it would take too long and be too complicated to explain that actually I am ok but Mum isn't. I think we do that a lot, hide how things really are with us; there are probably a number of reasons but sometimes its just that we don't want to bore or burden the other person with our troubles.
A friend introduced me to a tool that I think can help. The moodscope.com website was created for people with mental health disorders but I have found it useful too. It is easy to use and tracks your mood by means of your responses to 20 simple questions. You can make notes which will help identify the reasons why you are feeling the way you are and over time may help you to avoid triggers that make you feel low. (I inevitably have lower scores when I am tired.) Crucially, it also gives you the option of having your score sent to a trusted friend by e mail; the friend can then choose whether or not to get in touch with you and offer support. There is no obligation on them to do so but you have the comfort of knowing that someone somewhere knows how you really are.
If you find it difficult to express how you feel about your situation can I recommend you give this a go?