The hard thing about anxiety is that sometimes it is caused by a trigger and sometimes it's not. But when it is, it's episodic -- only that trigger is the problem. In your case, if you've become agoraphobic, it's chronic. While you may have noticed it because you wrongly believed you were having a heart problem that it appears you weren't actually having, a very common thing for anxiety sufferers, that seems for you to be just what you focused your anxiety on but the anxiety wouldn't have become free-floating if it wasn't already ready to break out. The reason you weren't cured is because your heart worry wasn't the problem, the problem lies elsewhere -- possibly some deep insecurity caused by something that happened to you, possibly caused by depression, possibly caused by nothing anyone will ever figure out. I'm wondering if, before you turned to medication and before it got this far along, did you ever seek out therapy with a psychologist who specializes in anxiety treatment such as CBT? As for the Lexapro feelings, these meds do have side effects that differ by the individual, but because you express such a fear of going on medication I'd guess this particular symptom, given it's the same one you've had all along and not something new, is due to your anxiety over taking the medication. You're probably not on a therapeutic dose yet -- 10mg is the usual dose for anxiety, though people differ in how much they actually need -- but you're tapering up on it is a very good idea and one your psychiatrist should have done -- this is pretty standard procedure with good psychiatrists. If you're doing this with a general doc, since they don't specialize in this stuff, they don't really spend that much time learning how best and safely to use these meds, but your instinct was better than whatever doc you're using. As for when you stop, that will depend on how long you end up being on the drug -- the longer, the longer the taper off will probably need to be. There is no standard taper, though docs do get hooked on using the same one for everyone they see -- the taper depends on how the individual is reacting. My own bias is for trying therapy before going on an invasive medication just as you would try physical therapy before getting surgery on your back, but if you're so far into this already that you're afraid to leave your house very often, you might already be at the point where medication is necessary. Only trying therapy would tell you that, but it does take some time, whereas when mediation works it works in a shorter amount of time. Also remember, the drug might not be the right one for you -- it can take time to find one that works. As for Buspar, it doesn't have very good clinical results and is mostly used as an adjunct to an antidepressant. Not to say it wouldn't help you, but it hasn't proven to work for very many people even in its own clinical trials. As for benzos, if you take them regularly, they are addictive drugs, so they are better used only on an as-needed basis. They are also hard to stop taking. My own experience is that benzos are useful for when you have to do something that is hard for you to do, but when an antidepressant works, it works all the time. Good luck whatever you try, and do consider therapy even if you do stay on the medication route -- drugs tamp down symptoms, but if you're one of the lucky ones who works hard and gets helped in therapy, you will be cured. Again, be optimistic, and good luck.
I have been on SSRI medications for 22 years. I have pretty much been on every SSRI on the market. Starting a medication can be scary, especially if you have anxiety issues and reading about side effects can make things 1000x worse. The meds really are quite safe. I've never had heart issues with any of them (even when I felt I was having issues with my heart). SSRI's, including lexapro, are very safe and very effective for a lot of people. I, personally have been on lexapro and for me, at the time, it was a life saver. Don't let your fear prevent you from trying the lexapro out. I know that is easier said than done but you may find it eases your overall anxiety which could very well help with your cardiophobia. I also have cardiophobia. For a long time I was checking my heart rate 15-20 times a day. I would totally freak if my heart rate went over 100 which it was 99% of the time. The reason it was so high was because of anxiety. The more I checked my heart rate the more anxiety I got which just made my heart rate go even higher. One type of medication I found helpful were beta blockers. I was on Atenolol for a long time with my paxil. When my heart rate got too high I would take a quarter or a half of my 25 mg pill and it would drop my heart rate into the mid to high 80's which greatly eased my anxiety. Beta blockers are pretty commonly prescribe for the physical symptoms of anxiety. They do have side effects and you do have to be a somewhat cautious but that may be something to look into to add to your lexapro. Anxiety is a funny thing. It can make you feel like something is wrong even to the point where you actually feel physical symptoms. Maybe lexapro will help you, maybe it won't. If it doesn't there are other SSRI's that may help you. I would personally avoid paxil. It works well but you may gain a ton of weight on it. I was recently switched from paxil to prozac and it was the best decision. You could try buspar but it's kind of a funny medication. It either works or it doesn't. It seems about 50% of people it doesn't work for and 50% of people it does. If it does work it can be a fantastic add on to an SSRI. You could also add on something like abilify or rexulti. There are tons of medication combinations that could ease your symptoms. A beta blocker might be a good place to start to give you a little peace of mind about your heart. Sorry for the long winded reply but I hope that something I said is of benefit to you. It sounds like you and I have a lot in common with our symptoms so I can relate. Trust me, with the right medication it will get better. You could even finally be able to live a normal life without having to worry all the time. Be strong and I wish you luck.