I took Lexapro for about 2 months and then I ran out about 2 weeks ago?

This morning I woke myself up at 6 feeling like was going to throw up and went to the bathroom and calmed myself down and I was fine. I didn't throw up. I fell back asleep fine. I woke up at 11:30 am and my head hurt and I wasn;t feeling so good. I ate and got ready for the day and I was fine. Then when I was about to leave for cl and I started feeling really nauseous. The whole drive there was such a blur. My head was hurting and I just started crying again. I called my dad then I felt better and the after cl I went to the store to get some food. I was feeling good and then suddenly I felt like throwing up again. So basically all day has been horrible. Random waves of nausea and headaches that come out of nowhere then once I "calm myself down" in my head I feel fine. I know this has to be my depression coming on again. Before I got the medicine it wasn't this bad. Now it seems worse since I ran out of medicine. I'm actually going to get more medicine tomorrow. So should I take pepto bismil today for my stomach or should I just wait for the meds tomorrow? ANd another thing, will I have to take this medicine forever? I really don't want to but thanks for your answers.