If Toprol isn't working for BP control, yes, you should go on something different. Since it sounds like you also have palpitation symptoms your doctor may recommend you stay on the Toprol and add something in addition to the Toprol that will work better for BP control.
Yes, you do not stop Toprol ABRUPTLY or it will lead to major "rebound" palpitations and high blood pressure. Instead you have to taper off of it very gradually by weaning down your dose over several weeks. I had to taper off 100mg twice a day and it took 6 weeks. Talk with your doctor on a tapering schedule, but good rule of thumb is 1/2 dose for 2 weeks, another 1/2 of that 2 weeks until you get down to 12.5mg. Then cut the mid-day 12.5mg dose, another 2 weeks, and then cut out the night time dose. I stopped after cutting out the mid-day dose and am still on 12.5mg at night. Note that your heart will race a bit for the first day or two after cutting back on the Toprol and these episodes can be a bit scary.
Of course you will need to figure out at what point during the tapering schedule to start taking a new medication so that your BP doesn't go out of control.
Work with your doctor on this. Tapering off Toprol can be tricky.