Birth control implant

Going to start birth control here next month or in 2 weeks.. depends.. we have been using condoms for 2 years now due to him NEVER getting the snip and when i had my c section 2 years ago i had so much scar tissue from my previous section and dermoid cyst removal they couldnt find the only ovary i had left! (My luck). Well i am looking at the arm implant due to my weight (over 230#) plus i have pcos and hashimoto thyroid. I dont want more weight bc i heard depo does that and pills arent as effective after youre over a weight #.

Advice for the insertion visit? Like pre medicate? How bad does it REALLY hurt? Etc... (yes i have tried and iud but due to scar tissue my uterus is pulled too high and i could perforate per my ob)