Welcome to SI and I'm sorry you're here. In the JFO (Just Found Out) forum, there are some pinned posts we encourage new members to read. There are some with bull's eye icons that are very helpful. The Healing Library has a lot of great information and includes the list of acronyms we use.
I'm sorry for the loss of your friends.
If you can, IC (individual counseling) with a betrayal trauma specialist can be helpful. Your WH (wayward husband) needs to be in IC, too. He needs to do a ton of work to figure out his whys and work on becoming a safe partner.
If you're having trouble eating, try protein shakes or anything to get some energy. If you have problems with anxiety or depression, see your doctor for some meds. Also, you should be tested for STDs/STIs. There are some nasty diseases that can turn into cancer.
The close friend need to be out of your life, pronto.
What your WH did was not a mistake, but a deliberate decision to lie, chest and betray.
Infidelity is the worst pain imaginable.
What do you want to do? You don't have to decide today, but you can think about it.
BW M 34years, Dday 1: March 2018, Dday 2: August 2019, D final 2/25/21