It sounds like there’s nothing more that you can do if you have already apologized and made an effort. Unfortunately these things happen.  Even though you meant well sometimes it’s better just not to get involved. It used to bother me a great deal  when friendships would dwindle or end. Now I have come to except that all friendships aren’t meant to be and all relationships  aren’t permanent.  I have found that friendships at work can be complicated at times  and many of the friends I had at different jobs were not friendships that continued when we no longer worked together.  Now that I am older I keep friendships at work very professional.