anxiety getting worse after birth

for years i’ve had severe anxiety and depression. before pregnant i was on prozac and when i found out i was pregnant my doctor switched me to zoloft. since giving birth (almost a week ago,) my anxiety has skyrocketed as all i have been thinking about is dying and aging and family members dying/aging (i have a fear of death&aging,) and also have found that i think i have separation anxiety of the baby because i am scared to leave my baby with anyone even my fiancé and when people come over to see him i get really uncomfortable because i’m not the one holding him. my question is, do i tell my ob at the 6 week checkup or do i have to pay to see a psychiatrist to get medicated for this stuff