Here’s what you do Joe,
First (and most important) right now decide to change your life. Call a drug helpline and talk to someone. You won’t be judged and they’ll find you support in your area.
Second, plan to use that support, rehabilitate yourself, zoom meetings, counselling. Work on your well-being
Third, tell your partner everything. She’ll likely be upset, angry but she also might support you. But you’ll have to listen to her needs. If you really love each other and you’re honest from here on in, you could become stronger
Fourth, live a new life. There’ll be hurdles, good days, bad days, cravings. But with the right support you can do it and in time you’ll hopefully see your children and be the best version of you. It’s 100% possible Joe