Hmm. I favour Seesaw's option 3 personally.

I haven't been in that situation myself but do have a friend whose male companion could not deal with her cancer diagnosis and disappeared leaving her to go through treatment alone. Some people are not strong, they cannot deal with these things, he simply wasn't capable of providing support. Afterwards he came back and she forgave him. He had his own weaknesses and struggles and she weighed the whole picture up and took him back - however he did apologise and acknowledged the hurt his abandonment caused her.

I personally would be very wary of anyone behaving as your 'friend' has. Lack of acknowledgement or apology is troubling to say the least.