I took Lexapro for 10 years. Always in the morning. It worked very well for my anxiety.
My cardiologist prescribed Coreg (a beta blocker) for my hypertension and secondarily for my anxiety. It has been helpful in both areas. Just don't take it on an empty stomach.
I am taking Zoloft. The first day I took it, I took it at night. I skipped the next day and took it in the morning the following morning. I like taking it in the morning because it makes me calm throughout the day and I can still sleep at night. The first time I took it at night I didn't sleep well. Now I take it at 8am every morning and then I am asleep at night around 10-11pm without any help of sleeping pills. It really just depends on how you feel for which time of the day, you probably already know that since you have been taking Prozac. I would think you would be ok taking Prozac and lexapro together. You could always take them a couple hours apart from each other if it makes you nervous about taking them together.
I take zoloft for my anxiety. I actually just was put back on it after being off for 2 years. I also take a xanax at night because my anxiety gets real bad then.