Singles Coping

i've been contemplating of doing an annulment with my wife for the past 3 years now. i met her in a substance-abuse facility and when we got out, we lived together and i got her pregnant. so i married her. after 2 years, she evolved into someone i do not know anymore. she's got hallucinations that everybody hates her and she nags me about not being sweet to her 24/7.
then i met this girl Trish, that was november 2010. she's a sophisticated, free spirit-type who meets new friends everyday. we fell in love and i was so guilty that she's been feeling like a mistress with the set up we have.
she's from another city and i visited her regularly.
i am very investigative with my questions sometimes and i sensed inconsistencies with her statements all the time. paraniod as i am, i began to suspect she's hiding something from me. then one day i found out when i forced-open her skype account that she has a boyfriend. and they've been together for 5 years now.
i confronted her and of course i felt betrayed, since i have started living away from my wife since her erratic moods was diagnosed with multiple mental disorders and staying with her could break me, her, or us both.
i found out that this guy nick starved himself when Trish left her 5 years ago. then after two weeks after breaking up with Nick, Trish got a call from one of Nick's friends telling her that they have to rush the guy to the hospital and everybody saw it as a suicide attempt.

Trish has this thing that she doesn't want to be responsible for the miseries of her exes. So she drove to nicks place and rushed him to the hospital.

Then, flattered that nick could not stand her absence, she put up a business for this guy and they've become partners and it was did good. when they got more than 500grand, Trish told nick that maybe it's time they get married. but nick said he wants to buy a bike instead.

Time came when nick asked her to marry him, trish realized she's not in love with him anymore. so she had boyfriends and nick found out all about them. they would fight. but when trish attempts to get out of the relationship, nick would warn her that he might kill himself again if she did that. so trish basically created a jail for herself.
everytime nick feels she's leaving him for good, he would always threaten to kill himself and all the time, trish would feel guilty and the cycle went on til today
.

for 6 months now, i have been turning into this monster that would yell at her, tell her she's a slut, etc. because i cannot stand the idea of sharing my girl with another man.
though she swears that they're not having sex anymore, i still turn into that monster and i would break up with her everynight when she gets home from nick.

when i tell her what she did at nicks place she would just brush me off and that made it all worse.

she said in that letter that even before she met me... she was already geared up into leaving nick. and she has done it so many times but nick would stay whole day in the rain in front of trish's office building untill everybody in the building knows the story and he would always satge an embarassing, pathetic stunt to get trish to get to him again.
so trish's only solution was to leave the country... and when she returns, she would get a new place in a different city and be gone with nick forever.

that's her plan she told me... but seven months have past and last night when i broke up with her again she said she'll do everything to leave the country february 2012. she said she would "try her best" to leave the country 3 months from now.

i cannot stand the fact she goes to him mondays thru fridays. on weekends i have her for myself.
but even after a romantic sunday. . mondays will always be like a stormcloud gathering on top of us both brewing the perfect storm that would last till friday.

we're both tired of this cycle of fighting and making up.... but we always wake up the next morning feeling how we love each other, patch and make up. till 4pm comes then my jealousy would rage again.

she's not explaining to me why she stays at nicks for 4-5 hours and hates me when i interrogate her about it.

she loves me, i know that but she can't give me the peace of mind i have been begging for since june.

the last 3 months i have been doing drugs to cope with the screwed up realationship i am in. i am beggining to get hooked again cos when i do drugs, i don't turn into this monster and im even sweeter than when im sober.

she said she cant leave nick because he might kill himself and her investment to the business they have is so huge she cannot just leave it in a snap. she says she loves me and tells me not to ask questions. she tells me she doesn't love him anymore and she loves me but she cannot be open with me.
i cannot stand her going to nicks place. whether it's business or her investment, i still get paranoid that they're still having sex.
i cannot stand it anymore. she's got no explanations for me. and no definite date as to when she's leaving the country.

she told me she's had bad relationships in the past that she cannot open up to me anymore. told me i shouldn't rush things and just wait till she leaves the country. and then maybe that's the time i can get the explanation i want.
should i stay or should i go?