I saw your question and double checked the information available on this drug, since it was not an antidepressant or antipsychotic that I had ever heard of.
In fact, it turns out that 6-APB is a 'designer drug' and it has not been evaluated by the FDA, in other words, there have not been clinical trials studying the effects of this chemical. It is thought to be chemically similar to amphetamines and methylendioxy compounds (such as MDA or 'ecstacy') and is thought to likely act as a reuptake inhibitor of serotonin, norepinephrine, and dopamine.
So as long as you are not taking any more of this substance, you are likely to experience a gradual decline of any symptoms you are over time, but since this is not an approved medication there is no clinical data on the pharmokinetics of this substance, and there is currently no way to know for sure how long you will have the effects that you are experiencing.
Regarding your blood pressure and your dizziness - people do sometimes tend to get dehydrated when taking substances in this class and as well people tend to get dehydrated in the summer more frequently. So, if you are not, make sure you are drinking enough fluids.
Feel free to provide an update on your blood pressure and situation, especially if there are continued abnormalities.
There are medications that could be prescribed to you to help if side effects remain uncomfortable. There are also medications that have been studied and the safety along with side effects are well documented, that have been shown in clinical trials to help the symptoms of depression that you might want to consider.
Again, please do reply if you have further questions. Since you have had two different experts with two different answers to your question, when you do reply, please address whether you would like to continue with me, Susan Ivy, or Nurse 72.