Bunny my dear you have NOTHING to feel embarrassed about. You know you're not stupid, but just like many of us you have been reeled in by a manipulative and plausible man aresewipe who can probably be extremely charming when he's trying to get his own way.
I mentioned before that I was done over financially (albeit in different circumstances, and emotionally too) by an utter cunt (I don't usually use that word but there's no other way to express the disgust I have for him) and I too was embarrassed and mortified that I could have been so "stupid" and gullible. I initially questionned if I had somehow bought this upon myself, or whether my misgivings were actually unreasonable ! I think it's natural to do that - even in the face of quite appalling behaviour from someone else - if you're a nice decent person who's been brought up to consider other people - and not just yourself as twatface has done. However, I eventually realised that I'd done nothing wrong and that my only faults in the matter - such as being too trusting - were born out of the desire to do the right thing, and NOT out of any malicious intent. The same could not be said of my exH who had deliberately plotted, nor can the same be said of twatface who has proven what an utterly mean and selfish "man" he is over and over again.
It does NOT matter what he tells others about you. If they are immature enough to believe him then they aren't worth having as friends. Indeed, if he is immature enough to go round washing his dirty laundry in publuc in an attempt to discredit you, that says an awful lot more about his true character than it does yours. Most people deal with relationship breakups with dignity, no matter what the background, confiding only in close friends and family who can be relied upon to be discreet, not who'd lap up the salacious gossip.
You KNOW you are NOT selfish and greedy. Where's the evidence of that ? Your friends and family also know this and they are the only ones whose opinions matter. Tell them everything, and I am 100% convinced you will be enveloped in a heap of love and support to help you through this. Don't give a stuff what his revolting mother thinks .... so what she might think you're a "golddigger" (ha ha ha bloody ha) .... fact is, you're the winner in this because you don't have to put up with her foul excuse-for-a-man son any more.
When I broke up from the cunt, I too thought I'd never want anyone else again. I was so appalled at my apparent lack of good judgement that I more or less hid away from the world - bar going to work - for over a year. I didn't want to go out with anyone, let alone have a relationship. But that time for me was invaluable because it was my own time, with no calls upon it from anyone else apart from my son, and I thought long and hard in that period about what I wanted from life, how I deserved to be treated, and what I would and wouldn't put up with. It made me stronger so that when I did start to date again, it was in a "I'm not going to take any shit from anyone" mood .... and in quick succession, I dated - and then ditched - 2 men for about a month each whose behaviour/lack of consideration rang alarm bells. Previously, I'd have probably been looking for ways to excuse them and wouldn have hung on in there while they took advantage but this time I just thought "sod it, I'm not putting up with this, why should I when there are 1000s of other men out there who could be better" .... and I can tell you, far from making me sad or unhappy, it felt bloody liberating to have reached that point in my head. I then met my current DP when I was nearly 37 and we now have a 6 year old DP .....
..... so anyway, the point of all that was that there are many of us who do understand how you feel but believe me, don't write off your future, or let the fear of that stop you from walking away from the twat. Just think of other people you know who've been through nasty splits - how many of them are still in mourning about it years on like Miss Haversham ? None, I bet, and nor will you be, I can guarantee it.
As to worrying (understandably) about the mortgage should he leave, please try to remember that any mortgage worries though unpleasant, are far preferable to remaining in the current status quo. What's the worst that could happen ? ...... notwithstanding switching, say, to interest only until the house is sold, and/or getting a lodger(s) to help with the repayments & bills, the very worst that could happen is that the house is repossessed .... and that's not a definite, by a long chalk, and frankly, I'd still say that's preferable to staying. One thing that occurred to me ..... if your parents were going to pay for your wedding, perhaps they'd help with the mortgage payments instead until the house was sold ? Just a thought .... I suspect they'd think this was a better use of their money actually.
Too damn right he doesn't want you to talk to them - or anyone else ..... 'cos there goes his "reputation" for one thing, and there goes your compliance for another when everyone and anyone you shared this with would point out how appallingly you're being treated. Another great big alarm bell ! If he had the courage of his convictions and genuinely believed that his behaviour was acceptable he wouldn't care who you spoke to about it would he ? ..... the fact he does care tells me that he knows (but obviously won't admit it to you) that what he's doing is very fundamentally wrong yet he still does it .... which is all the more chilling.
Come on Bunny - you can do this, and it will feel like a weight has been lifted from you I guarantee it.