How to give 2 week notice

So I’ve been at my current job 2 years and I’m just very miserable being there. I thought it was because I was pregnant and hormones so I stayed during my pregnancy. I came back from maternity leave 4 months ago and it’s really not just my hormones. So I ended up having a friends boss offer me a really good position with really good pay. I ended up saying yes, I will take the position as I’m just not happy at all. They want me to start asap. So I have to give my 2 weeks this week. Well Monday I was off for my birthday and when I went in yesterday my coworkers had gotten me a gift certificate as well as a cake. It was very kind and I appreciate it but now I feel bad for giving my two weeks this week.

How would you go about this? I get extreme anxiety when leaving a job only ever left one other job. My anxiety causes me to stay at places for years and years until I’m just so mentally drained. This job has been affecting my mental health and physical health for just too long.