I am rebuilding as well. I had to demote out of D.III to do it though. Then I took a break from the game... but thats a whole different story.
Before I started playing again, my record was like 0-14, with only one good player on my team. I have spent no money on the draft this season. What I did is buy a bunch of old guys who go for almost nothing. I have won my last 2 games in a row (my only wins this season) and am probably going to stay in my league via regelation series.
What I would do is buy a couple of 31 Y/o for 50k-70k each who would be decent starters in your league. Also, get rid of that trainer. If you phase out the 34 Y/O+ guys slowly with some 31 year olds, you wont take a huge hit financially. Also train your three trainees. I have no clue how developed those trainees are, but I would single position train them. In three seasons, they will be capable starters in your league. Do not decide to tank. The money in division IV is soooooo much lower.
By the time your 31 year old starters skills have diminished to a point where you cant use them as starters, your trainees might be able to step in, or you can sell that 33 Y/o who you bought for more than half of what you bought him for.