Gabapentin and pregabalin can be quite effective for generalized anxiety. Doses vary alot from person to person, but I have seen people on up to 3000 mg of gabapentin and have no problems. Gabapentin is very safe as it does not interact with anything due to its renal metabolism. Having your PCP prescribe is safe, but probably not as effective as a psych. There is an art to psychopharm, so if your PCP prescribes alot of psychopharm he/she will get the hang of dosing, when to use what med etc... In my work in primary care sttings I co-prescribe with PCP's, and help teach them the art of psychopharm, and it works quite well.