Suggest Treatment For Heart Palpitations After Reducing Dosage Of Lexapro

I have been on Lexapro 20 mg for a while now, for my anxiety attacks. it helped mostly, but still had some panic with the Lexapro. I felt like my heart had begun racing, ran tests, nothing... except the Lexapro... so I started lowering my doses without a dr s approval. I got down to 5 mg and felt great, I did have withdrawal symptoms at first but they have lessened as time has passed. although now when I get nervous about something, my heart races and wont stop, I feel like I am going to have a full blown panic attack, a big one... my heart not only feels like it is racing but feels like it is beating HARD... I am working on managing my panic, but it just seems impossible. I get excited in any way, good or bad, I walk too fast, I get in a hurry... here it comes, the racing heart, the flash of heat and the panicky feeling overwhelms me. HELP ME