I just can't take it anymore, I've been wrangling with the idea of leaving for years and always bottled it, hoped and prayed things would change, thought it would be better for DC's to stay together, changed everything about myself to make him happy. Nothing has changed and I can't do anymore so why do I still have doubts 
A bit of back story, h and I have been married for nearly 20 yrs it's our wedding anniversary next year. We've had our ups and downs, h had an EA with someone I knew a few years ago. I have no idea why I decided to give him another chance, although he made out at the time that he was giving me another chance! At the discovery of the EA he told me he loved her and had fallen in love with her before even meeting her. (They'd made contact via internet, emails, text etc at first)
I think I just went into panic mode and changed everything he said I was or did to please him. I've kicked myself over the years for allowing myself to be fooled into believing his lies and accepting his deceit but once I'd made the decision to work at our marriage I felt I had to stay.
He took up fishing a couple of years ago and began secretly buying things of high value and hiding them, lying about the cost or that he'd got them given to him etc. I discovered a huge purchase of £950 he'd made that he'd tried to hide from me and it all kicked off. It's not the buying stuff he wants that's bothers me so much, except that we can't really afford it, it's more about the deception and lies and the covering up that goes with it. It upsets me that he's so secretive and told him that we need to be open and honest with each other about things. Hiding and lying just causes more trouble and upset. He says he does it to protect me, so I'm not upset or angry at him but that upsets me too.
He promised me a couple of months ago that he would be honest with me and not hide things or lie anymore. I said all I wanted was transparency and that past events made it difficult to trust if he continued to deceive and lie to me. He says it's totally different, it's not ow it's just a hobby so I shouldn't have a problem. Maybe he's right but it is a problem to me :-( I'm totally honest and upfront with h and just want the same respect.
Today I found out he's spent another £290 on his hobby and tried to hide it from me, when I asked him if he'd been buying fishing tackle again he was all evasive and asked what I meant, I repeated the question and he said why do I ask? I said I just wondered if he had or if he was keeping to his end of the deal a out being honest with me. He went silent and began fumbling around the kitchen trying to avoid eye contact. I couldn't say anymore I was so upset that he'd done it again.
I know this probably sounds ridiculous to people to end a marriage for something that sounds so trivial but he's just ground me down with everything. He hates me doing anything, he wants to involve himself when I chat to a friend on the phone, asks who's texted me or rang etc. I feel like I'm under constant observation and interrogation yet he can do anything and everything he wants and I should just smile and nod.
Separating is going to be an absolute nightmare and I don't know how the hell we're going to sort it out but I can't cope like this anymore. I'm gutted it's come to this. I married believing it would be until death do we part and I feel like an utter failure for giving up but I haven't got the strength to fit for it anymore :-(