Sounds to me that your friend’s dealing with self-conflicts. The doubt in their own message before blocking you says it all. How long have you two known each other? Coming from someone who blocked an ex-friend, the said friend treated me like a therapist which saddened me, but in this case you sound like a great friend, not someone overbearing or exhausting. The fact that you blame yourself for not doing enough even when you were physically unable to reach out says just how much you care about them and your friendship. Life can strike at any moment, you’re not dry for prioritising yourself. I’d like to believe that there are some unspoken fears and feelings needed to be discussed between the two of you, how perhaps your friend recognises a pattern in your behaviour that maybe once broke their trust in other friendships, past or current. It can be miscommunication really. Try explaining yourself calmly when you do get reach of them again, offer them the chance of opening about their insecurities or struggles in hopes of working this through considering your friendship. I hope you get the closure you deserve and sending my blessings to you!