Infidelity with a child

This sounds very painful; you're not only grieving the affair—you may also be grieving the marriage you thought you had, the trust you placed in him, and the future you imagined together.

• Please don’t pressure yourself to “forgive” quickly. Forgiveness, reconciliation, and rebuilding trust are three different things. You can eventually forgive someone for your own peace and still decide that the relationship needs boundaries, separation, or major changes.
• Be gentle with thoughts like “My whole life was a lie,” “I should have known,” or “I’ll never recover from this.” Betrayal can make the mind go to very painful extremes. What happened is serious, but you do not have to decide the rest of your life while you are still in the shock of discovering it.
• Ask yourself: What do I need right now to take care of myself and live according to my values? Maybe that is honesty, dignity, emotional safety, protecting your children, getting support, or simply allowing yourself time before making any major decision.

I would really encourage you to speak with a therapist or another mental health professional soon. Therapy can give you somewhere safe to process the betrayal, understand what you want, and make decisions from a calmer place rather than from shock and pain.