CandyCane,
I know you said you have been focusing on your hair for years, so I can definitely understand your frustration. Another poster asked you about relaxers and another suggested that maybe your hair doesn't do well with relaxers. This started ringing bells with me, because in your post you noted how thick your hair is at the roots. So obviously your hair is growing in healthily. It maybe the brand of relaxer you use (motions does not work for everyone and the motions oil has mineral oil in it and caused quite a few problems for people on this board). So it could be a matter of switching brands. But it may be that your hair does not respond well to relaxers and you may need to think of ways to stretch out the relaxers or transition from them all together.
Also, You said that you wash your hair often, are you using shampoo each time you wash? Start by following the advice of working with only one shampoo for four weeks, but also try cutting the actual shampoos down to once a week and do either rinses or conditioner washes the other times. Also, you only really need to shampoo the scalp and root area, the length of your hair doesn't need it because the shampoos tend to dry out that area and it is already dryer than what is close to your scalp.
Someone also recommended that you stick with ORS hair mayo as your conditioner. This is a good idea, and I have just one suggestion that you may also like to try. Since you do pretreatments with oils, try adding a little Extra Virgin Olive Oil, a little bit of honey, and one egg yolk to the hair mayo and use that as a pre-treatment. Then you can follow with a more moisturizing deep conditioner. This is just a suggestion, ORS as a deep conditioner alone didn't really give me the softness and slip that I needed so for me this worked much better as a pretreatment. The Honey, EVOO, and egg yolk was something that I had been doing as a pretreatment before I ever heard of the hair mayo and I got great shine and softness as a result. Adding the Hair mayo boosted both of those things. So it is definitely something to try.
Also, how are you setting your hair? Sets have a great deal to do with how your hair looks as well. Rollersets are the best for giving your hair body and shine, but they take some time to master. It helps if you have another hair minded friend to help you out with that. Or, you can go to a stylist for simple wash and rollerset (this option gets expensive, but if you watch them carefully, and ask the right questions you can eventually start doing them yourself)
What I don't think has been asked is are you doing your touch ups yourself? Now I am a self relaxer because I had too many bad experiences with stylists, but I am also the first person to say, you really should have someone else do this for you even if its a family member or friend.
Now the part I was dreading: Have you considered a really good (maybe layered) cut? If you know of a stylist that you can trust or at least one that has been recommended by a friend whose hair you like, they may be able to work with you. Sometimes, starting with a good hair cut is the best way to go about acheiving your goals. Especially since from the sounds of it, your new growth seems to be in good condition. If you aren't comfortable with the idea of a full hair cut, maybe you could start with trims and trim more as your hair grows.
Don't get discouraged. Your hair is obviously growing, its just a matter of keeping it in good condition.