it depends how long your ex was dosing you, and how much she was giving you. If she started with a small dose and given it to you regularly for months and then gave a one final whopping dose when she realized you were leaving you could indeed have lasting changes to your dopamine systems, leaving you feeling indifferent, blank, unmotivated, and unable to enjoy subtle pleasures. Even a single whopping does- and it sounds like she did give you a whopper- can cause disruptions in your nuero chemistry for several weeks, and could easily produce psychotomimetic symptoms including severe anxiety, paranoia, and physical symptoms like racing heart, insomnia, feeling "empty" or "blank", fear of impendoing death or harm etc. The good news is you are not an addict, and you are likely to both abstain from using more drugs, and taking sensible wsteps to recover. The body is resilient, especially when given good nutrition, rest, exercise and medicine when necessary. You should make sure you are getting regular physical exercise that causes you to break a sweat, which promotes your dopamine/endorphin systems to repair and will helkp you start to feel normal. Try not to let the harmful lingering aftereffects turn into outright obsessions- you are going to get better, probably sooner than later. People take huge doses of meth multiple times a day for months and years, and many of them stop at one point, and are still able to more or less recover...I mean I wouldn't recommend it, it is definately Russian roulette, and lots of people don't recover, but just to put your own exposure into context, you likely were given too much, were not used to it, and possibly given a less than clean/pure form of the drug. The effects of meth are particularly long lasting, especially with large doses. But you will recover. It is exceedingly unlikely you will suffer any permanant or long term harm other than possible trust/fear issues that come from being poisioned by someone you trusted. You may want to seek early professional help for this before it becomes a problem of its own.