I cannot find Dogmeat anywhere after sending him to Red Rocket, I literally have searched every possible settlement of mine. Placed bells in the middle of each and waited to see if he showed up with no luck. The only thing i can think of that is that he is glitched somewhere because all of my settlements he would go are completely fortified with walls & buildings, I did delete all of the dog houses in the sanctuary before he was dismissed which could be an issue. I need him to continue the Nick Valentine quest and after searching everywhere I can think of and waiting about a week in game time, I have no idea how to find him. I cannot go back to the save where I last had him because it would literally put me back 48 hours of actually game play which would be complete bs. Any suggestions or help on how to find him would be greatly appreciated.

He should approach you once you leave Kellogs house whilst doing the quest. Even if you had another companion with you. Try going back there to check

Yes, for that particular quest, after I talked with Nick and mentioned somethng about Dogmeat, when I walked out the said pooch was happily welcoming me in the Diamond city just outside the door, while it should have been chilling in the sanctuary. So yeah, try to just advance the quest and if you can't find it even then, there are some console commands to try and solve it (which I'm not expert with)

And this surely should have gone to the spoilers board, what with you mentining quest workings in the opening post.

Thanks that worked, would of saved me soooo much time if It told me that before hand lol. And i wouldnt exactly call that a spoiler....I just mentioned a quest with not a single detail actually about it, unless you wanna go technical just because i said the dog was involved lol.