I don't believe the risk is the same with l-tyrosine as it is with something like 5HTP. I've actually heard it DECREASES serotonin, but I don't know enough about it to be honest.
To be safe you should check with your doctor or pharmacist. Obviously, if you feel noticeably worse since taking it, you may want to reevaluate it.
At the very beginning of the Thomas Recipe there is a warning....that says if you are on an antidepressant, you should confer with your dr. before taking l-tyrosine, 5HTP, or any other mood enhancer.
The Thomas Recipe also says you "may" take "up to" 4000 mg...but to scale up or down as needed. It also states if you get the "coffee jitters" to cut your dose down. There is even a statement about l-tyrosine causing the "runs". As far as a "interaction conflict" with your zoloft.....if cutting back the l-tyrosine doesn't calm you down.....I'd call your doctor. It is strictly my opinion, but I'm thinkin you will feel alot better if you scale back that 2000 mg dose. Here's something I read about taking zoloft as well as l-tyrosine:
"The two substances have more differences than similarities, but they share one characteristic -- they both affect neurotransmitters."
I would NOT be concerned about seratonin syndrome (I had that...and it was from taking too high a dose of an AD prior to and for the first week I was on subs...there was even a warning in the sub paperwork that advised against taking an AD while on subs. (that's why I questioned my sub dr after the 1st week on subs)
I don't remember how long you have been off the subs but if I were in your shoes, I'd definitely scale down or stop the l-tyrosine for now and I bet you feel a lot better.
Blessings to you~