Hello, I Have Recently Been Prescribed Doxycycline This Past November

Hello, I have recently been prescribed doxycycline this past November (2016) for chlamydia.
In early spring of 2016, I was diagnosed and given both Doxy and amoxicillin twice and have thrown up the medicine numerous times resulting in my condition untreated. This time around I have been advised to eat the medicine with food to prevent sickness (I also have been prescribed ondansetron for nausea) I have not yet taken the medicine due to an extended vacation out west and limited control over my diet. I have three questions for you: for one, is the medicine still okay to take even though it has been over 2 months since prescribed? and also, which foods would you suggest I could eat the medicine with? And finally, when should I take the Odansetron? Should it be with the food and thirty minutes later take the Doxy? I am finally home and able to control my diet completely. I am in need of advice, I hope this summary was clear enough. Thank you.