Laryngitis or bronchitis ??

Ive been sick for over a wk now. I took my 5 mth old to the dr. last tues with a bad cough that he had for over a wk...they told me he had a cold. Well hes better now, but ive been sick since last tues. I thought i had a cold and cought it from him but ive been coughing soooo bad, and ive lost my voice and its been pretty much gone for 4 days now. I dont feel sick....i just feel exhausted. Ive never had either of these, but friends think one of these is what i could have. Also are they contagious??? And are they treatable at home???? Are these things i would need to go to the dr. for? Sorry about all the q's, but i have know idea what to do and would hate to go to the dr. for them just to tell me its something stupid and waste my $30 copay. Thanks for any advice.