i think all you can do is learn from your mistake. beating yourself up doesn't really help once you realize your error. as for getting over the guilt you could talk to a pastor or priest or even just to God if you are inclined that way. we're all human and we all screw so please don't continue being hard on yourself. i don't think you need to tell your new boyfriend though and it might freak him out at this stage in your relationship. maybe a ways down the road you can tell him and he'll understand. he may not though. your therapist truly gave you terrible advice, and i hope you have fired him.