If you really want to become a pharmacist, you will have to assure to yourself that this pre-pharmacy will take you 2 to 3 years to prepare. Since you wrote you had to practice the problem 10 times to understand, and you also have severve personal problems, I would suggest you to solve your personal problems prior before you do your pre-pharmacy. Why? After 2000, pharmacy schools have received thousands of applications, getting in pharmacy school is highly competitive, and the PCAT is also toucher.
Since you had an F in one of your classes, and going to receive some bad grades for others, I think it will look bad in some ways, but I do not believe if you can't do pharmacy. However, you may need to retakte the classes to demonstrate that you have sufficient knowledge to succeed in Pharmacy school. Work or Volunteer in retail pharmacy will definitely help you. Remember, nothing is impossible unless your mind says "No" to it.
I will tell you briefly the process of applying to Pharmacy school:
1) Each school requires you to take 60 credits or more. Classes are varied depend on schools.
2) Take the Pcat which is Pharmacy College Admission Test.
3) Have 2 or 3 Letter of Recommendations from Professors or Pharmacy.
4) Apply through PHARMCAS.
You do not send your application to the school, but you have to do all your papers through Pharmcas, and then Pharmcas will send everything to the school.
5) Receive the secondary application from the school.
6) After finish and summit secondary application, wait for an Interview.
7) After an interview, wait for thier decisions.