Fallout 3 jericho disappear?

ok so after i went to vault 112 with jericho i got in the pod and did the good ending and i got out and talked to dad and jericho was there when i got out but i started to follow liam neson outside and i fast traveled to rivet and ever since jericho is not with me (sidenote i have neutral karma) and megaton is...well...gone if you know what i mean. please help he had deathclaw hands a plasma rifle and combat armor...if i cant get him back please tell me where i can get another follower