Regardless of the fact that you acquired the property before your marriage and that it has subsequently become the marital home, as you are the sole owner of the property your h has no right to remain in your home without your consent and you are therefore at liberty to change the locks or ask the police to remove him as you see fit (if you have family/friends onside it should be a relatively simple process to effect his speedy removal without calling on the services of the old bill).
With regard to any claim your h may have in law upon divorce proceedings in relation to your pre-marriage assests, when it comes to deaing with matrimonial property the Courts have wide discretion and flexibility and, in certain case, it is possible to exclude premarital assets from the division of the overall matrimonial assets either in whole or in part.
Given that your marriage is currently of only 18 months duration, I would suggest it can be argued that the marital home is a premarital asses that should be excluded from any settlement but, in the unlikely event that a Court should decide otherwise, I suspect it will determine that any sum awarded in favour of your h in respect of matrimonial property/assets will be minimal if not negligible - and it should be noted that you will undoubtedly have a claim in law against him.
However, each case is different and as the Women's Aid national helpline is frequently over-subscribed; search 'womens aid' followed by your county or nearest town to obtain the number of your local WA offices, give them a call and ask them to recommend solicitors who specialise in divorce and family law and who offer a free half-hour consultation so that you can find out for yourself where you stand with regard to the ramifications of separation/divorce - at the very least you should begin to feel empowered by taking matters into your own hands and this may help you overcome any feeling of ennui caused by becoming bogged down by a twat who sounds like a sociopathic Walter Mitty.
Sadly, I note that having given more than sufficient reason in your op as to why you should cut your losses and get out of your considerably less than fulfilling marriage without further ado, it seems that you're already talking yourself round and around into more dithering by bringing into play issues such as your need for childcare when you return to work, etc.
THAT, my dear girl, is NOT the way to go about it because if you keep on truckin' around that circular road years will go by until, before you know it , you're waving your dc off to uni - and you'll then wake up to the unpalatable fact that each passing year that you have failed to rid yourself of the unnecessary drain on your energies your h may significantly entitle him to benefit financially from the property that you scrimped and saved for.
Once you have metaphorically put a stake through the heart of the vampire that is sucking the lifeblood out of you, you will shed the skin of the woman who 'can't' and become, once again, a positive and resourceful woman who 'can' - and that woman can do anything she puts her mind to, including sorting childcare for her dc to fit in with her working hours.
In support of BayPolar, not all women are the weak and feeble creatures some would have us to be and I certainly would not tolerate the continuance of a relationship such as you have described for one minute longer than necessary.
You and your dc deserve the best - please don't make the mistake of so many who fall into the trap of 'better the devil I know' because you can easily find a man who will treat you infinitely better than the one who is currently making your life a living hell.
Wise up and get smart, honey, because if you don't you'll only have yourself to blame if your life continues to be less than what you know it can be.