You always get head lice from other people, but it need not be from direct contact - it can be from towels or pillows or head-rests. Even when it's from direct contact with other people, it need not be very close contact - if your hair touches someone else's in a crowded street, that's enough.
If they are not treated, they itch horribly, and your close friends and family will get them too.
You can get someone else to inspect your hair for lice, or you can use a lice comb vigorously while leaning over some paper and you'll probably see them. The easiest thing, if you suspect lice, is to buy some lice shampoo and use it and see if the itching goes. Even if it says it works on one application, use it at least twice, a week apart. At the same time wash your pillowcases and sheets and upper clothes, and treat other members of the family also.
It does sound like you have lice, though it could be something else.