am i better off without him?

[scaredsilly]

hello, i'm new to posting but i've been reading for several months. i'm very confused at to what to do. my husband told me in december that he wanted a divorce. we have been married 14 1/2 years. he has three children and i have one. all are adults. however, he is 9 years younger than i and his kids are younger. we have always had difficulties with how we each view his kids. they were with us every other weekend and all vacations for the first five years but i could no longer take them on vacations after that because it never seemed like a vacation to me with them along. i did all the cooking, cleaning, laundry, grocery shopping, etc. whenever they were with us.
near the five year mark, we sought marriage counseling because we let our different feelings about the kids come between us. the counselor advised my husband that the marriage had to come first. my husband thought i was too strict with them (i expected them to brush their teeth, make their beds, and pick up their clothes and towels off the floor and that's pretty much it). my husband would reverse things with them that i had instated (no computer for the day because of fighting over it) without talking to me first. he was the good guy, i was the bad guy.
when each child's child support check stopped, their mother would move to a smaller house with one less bedroom. when the middle son got kicked out (age 19), i suggested we take him in with us. it was ok, not ideal, but he was a pretty good kid. when the youngest got kicked out, i suggested she come with us, too. shortly thereafter, the son moved out and we only had the daughter (age 20 at that time).
the daughter, who had really been my favorite of the three kids until she moved in, became very hard to live with. she was moody, sullen, ungrateful (would bring her boyfriend over and cook for him on a regular basis without any contribution to the food, would have girlfriends stay with us for days at a time, all without asking or contributing), and manipulating. her attitude was completly different when her dad was around. he would work out of town 6 months of the year and during the day when he was in town. i was retired so it was mostly her and i together.
our relationship continued to deteriorate and i wrongfully took it out on my husband. i felt trapped and did not know how to get her out since i knew he did not want to make her go. the final straw was she she pointed to her father one morning and stated loudly and firmly to me, "what's his is mine!" i finally suggested we sell the house and move back to another home we have. that's when i told him i could no longer live with her. i was very afraid he would choose her over me to live with. to my surprise, he suggested we put her up in a rental we own (kicked out a very good paying renter) and let her live there for a very small rent (to cover taxes and ins.). this is the first time she has had to pay for herself as we let her stay for free with us (even though she has an inheritance in the bank of over $10,000 and did not work for the first seven months of living with us). she is a college student and all her education is pre-paid.
she lived with us for 2 1/2 years and her brother for 2 years prior to that while he was in college. all totaled, it was 4 1/2 years of living with adult steps and i became bitter and resentful (mostly, the last year).
even after we moved back together, the damage was done to our relationship. i think my husband feels that i would never be able to have a good relationship with his kids and that they (mostly the daughter) would not want to be around me so he's giving up and "wants to be happy". he says there's no other woman.
when he told me he wanted a divorce, i lost it. i did all i was not supposed to do; beg, cry, ask for another chance. i think now that i was mainly feeling abandoned. he had always told me that if i helped him for the 11 years he had to pay child support, he would support me for the years after i retired and that he continued to work.
since i've had time to reflect, i've come to believe that i will always be in the "backseat" and he and his children will come first. he refused to go to marriage counseling because he said that the last time we went, "i had to do everything". pretty telling. he does not want to stop dealing with his marriage and kids the way he wants to do it and a MARRIAGE counselor may tell him that it would be necessary to save the relationship.
i've read DB and DR and am reading "relationship rescue" by dr. phil, plus several other books ("getting past your breakup: how to turn a devastating loss into the best thing that ever happened to you"). any thoughts? y'all are so very wise and patient.