Your DH will need more time OP if you want a quick amicable divorce.
You do have a responsibility to not make him homeless and without an office in your short timescale.
Plan for a year.
And DO call an independent mediator. The lawyer will only be trained up to such a level, but you need a fully independent, accredited and trained one to get a win win you can hold your head high about in your future.
Stop plotting and get honest, fair and slow down. You can't evict a tennant on your timescales after 14 years occupancy, and you cannot evict your DH on that timescale.
Slow down, cool off, and get talking with an independent mediator not your lawyer
You need a win win, so work towards that as your best result.
If you railroad your DH you may end up with a totally fraught and unnecessary long, expensive and unpleasant experience.... a lose lose.
Slow down and be fair, put your irritation to the side and treat him as a friend, you won't regret it as you'll be divorced to him for the rest of your life.