Reached level 32, mainly playing as a Minuteman General, decided i needed a change so went to Cambridge Police station to take up Paladins offer to join the Brotherhood of Steel, after a bit of dialogue i was given my first task to recover the Haptic Drive from Corvega Assembly Point, i achieved this and went back to Cambridge to report my success, on returning inside the Police Station i could hear what sounded like a load of junk being thrown around and my game looking like i was under the map or something, sometimes if i keep moving very slowly (i can't move fast at all) i can make it into the Police Station but when i look around at the door i have just come through there is a pile of junk and debris blocking it and it cannot be moved, even though i report my success i cannot get back out of the Police Station, if i look out of a window it looks like i am looking outside at the unfinished bits of the map, i have tried reloading the game but the same thing happens all the time, i tried going off and doing more minute men tasks hoping it had put itself right when i eventually went back to the Police Station, i even went into Steam and verified the game files, all to no avail, this is really frustrating because i know i will not be able to complete the game as i would wish to now, the only other thing i can think of is reinstalling the whole game and starting from the very beginning but after playing so far for over 80 hours and reaching level 32 i do not really want to begin again, i would really appreciate any help i can get here...thanks

Have you tried exiting through the garage?

Or go up on to the roof and fast travel from there?

Sorry for the partial help, but I'm not too familiar with how the console commands have changed between Skyrim and Fallout 4. There should be a way to enter the console and type "noclip" or "NCLP" or something similar that will make the player ignore collision and gravity. You can then levitate back into the game world proper. Enter the command again, and you'll drop back to the floor and be able to continue playing.

Fast-traveling to a new location is another option, if you can fast-travel from that location. That should respawn you in the right spot.

Saving in such a glitched state is a VERY bad idea, but if nothing else works... Make a NEW save, then exit back to Windows, restart the game, and load. That can clear things up, sometimes. Be sure you IMMEDIATELY save in another NEW slot, then DELETE the other save. It's very easy to wind up with corrupted save slots if you save while experiencing a bug or glitch.

In general, be sure you have your frames locked to 60 and that your refresh rate is also set at 60 Hz. The engine (physics, especially) can wind up glitching out all over the place when frames are dropped because of high FPS / draw rates. Bethesda games only work stably at 30 or 60 FPS, and the display's refresh rate should be 60 Hz (not 120 or 144).