We really can't diagnose you over the internet. Celexa, as with all ssris, takes about 4-6 weeks to work for the average person. But the diagnosis of anxiety and panic attack is something I have some question about -- you say this just started 4-5 weeks ago? That it is always and only connected with eating, in your opinion? That isn't indigestion, because nobody gets indigestion after every single meal and indigestion doesn't cause anxiety attacks. So were you an anxiety sufferer before this started, or is it new and you believe only connected with eating? In other words, have you been sitting around worrying and avoiding things because you're scared and anxious for a long time, or is this just happening now? Because to me it sounds like a blood sugar reaction or some other reaction your body is having to eating, it it's something new and you didn't otherwise have a chronic anxiety problem. If so, celexa won't do a thing for you and the diagnosis of anxiety attacks isn't correct. It's very easy for a doctor to say you have anxiety and dismiss you with a pill. It's harder to find something physiological going on that isn't easy to find. Can you further explain, therefore, exactly what's going on and whether you've been a long-time anxiety sufferer? I would also, if you do turn out to have an anxiety problem, see a psychiatrist for drug treatment or a psychologist for therapy, not necessarily a primary care physician.
Lots of people get indigestion, which can be frightening, so this may be the problem that needs working out to solve the rest. What did your doc say about all these digestion issues that you say has been occurring over the last few weeks? Also food does not make you spacey, sweat, flushed, sweaty, or twitches, so that part you describe is all part of anxiety working you up into a fear attack and over-analyzing every body part along with the effects that indigestion is having on you - Don't get me wrong though, indigestion can be terrifying and depressing because you fear there is no end to it which can create the panic you are experiencing..
Celexa, is an SSRI and only provides LT relief, It takes up to 8 weeks to get full benefit from Celexa because it builds up in your body so not surprising you have not got relief yet. I would go back to doc and talk this out, because before it builds up it is a good time to go off it under his supervised tapering off method if you want off after talking to him.
The fact you know nothing about this med (did he not explain the build-up method the med works or did you not understand?) is surprising, which is why I would do some research with him on why you are on it.
Perhaps he did the right thing - it is not my place to figure that out from here, however if he wants you on meds imo he should have at least started with something for ST relief or had that as a backup while the Celexa builds in your system. Plus Celexa might work for one person but not another, so you might have a few drug trials to live with before one shows up that your system works well with - but that is another story for a month down the road if you give up on Celexa..
Therapy is a better place to start if you just started getting this issue, because meds should be a last resort. Write back with some more info so I don't steer you wrong with this advice.
I am guessing that HBP is not caused by a panic attack but you can read up on that to be sure. Here is a link I found right now suggesting there is no physical damage from panic attacks although Mayo Clinic.com is where I usually go for answers, so recommend you go there too for definitive answer. http://www.calmclinic.com/panic/blood-pressure