It's extremely difficult... been there many times... but you need to ask God to help you forgive yourself.. and do whatever it takes to make yourself feel peace... cos God has already forgiven if you ask genuinely... Sometimes you think you've asked too many times and God is tired of you, but God is not human... He can't get tired of you... He can't not forgive you... no matter what you do.... That's why he is God... Remember.. God pays way more attention to your faith, than your sins.... As humans, we are bound to sins.... we just have to get up and keep going...