How could the gods be so mean? :(. I think Fenrir should have been cared for the right way. I believe that if Fenrir was treated nicely he wouldn't be so hateful to the gods. If I was Fenrir I couldn't bear being betrayed by Tyr, as Tyr was the one who cared for Fenrir. I feel sorry for the wolf god.
Odin knew the future, that one day Fenrir would be out of control and would be the cause of his death. This, and the fact that Fenrir grew rapidly and large and became powerful, caused fear within the Aesir. They bound him as a means of preventing the future Odin saw from occuring, however, it is because they found Fenrir that the future occurs as it does in Norse literature and Fenrir goes on to kill Odin after holding a grudge against him for many a year.
I do not recommend channeling Fenrir, since you are new to the practice and do not have a full understanding of Fenrir yet- but I have wrote about it before. I use this as a method of channeling anger out of myself and giving it up as an offering to him:
Well I`m not really sure what to say one the subject, as a god Fenrir is a rather dark but also fairly easy to appease.
You don`t actually need an actual altar but as was mentioned before a tree, meadow or any place that is natural to wolfs, as for offerings some meat, fruit, ale and one can also offer a few drops of blood drawn from there left hand.
Also playing music or singing at the place dedicated to Fenrir can also be considered as a form of offering(only if the music piece was played or singed by the one giving the offering even better if you are the one to actually wrote the song/poem)