Sarahjoyhere, first off is getting her spayed. Cats can get pregnant as early as 5 months. If you think the yowling is bad right now, it will be about 10 times as bad when she first goes into heat.
About the breakables, I’d use the double-faced sticky tape and museum putty (or clay; FIMO is easily available at Hobby Lobby or other craft stores). That will help a lot, with teaching her not to jump up where you don’t want her, and from accidentally brushing items with her tail & breaking them. Personally, I keep all of my breakables in an antique china cabinet – and I don’t keep them out on top of the china cabinet, either. If you have stuff on a windowsill, I can just about guarantee she’s going to knock the stuff off; it’s much better to relocate the items than to have them break.
Most cats don’t like to play with toys unless they’re moving. This is why so many cats don’t play with them; until you animate the toy, it’s just not interesting. Do you have a cat tree/tower by your bedroom window? That would help a lot with boredom, especially if you did something like hang a bird feeder from that window.
Lots of playing and food before you depart for work will probably help her sleep while you’re gone. But if she’s locked in your bedroom while you’re not home, is she responding to your roommate? She may mistake sounds of your roommate in the apartment to be you – and of course she wants to see her mama! If you or your roommate is home, I’d give the kitty the roam of the apartment. A radio will help mask noise, too.
Last, please make sure you have a solid plan B and plan C in place, for when your landlord finds out you have a cat. (There’s only so long you’re going to be able to keep your kitty a secret from your landlord – especially if the downstairs shop owner complains to the landlord about the noise.)