Hi SofiaD, welcome to the forum.
I don't see there's anything to be anxious about. Your TSH is in the right place if you have antibodies, your FT4 may be too low, but as you don't tell us what it is, I can't comment.
Don't panic about the antibodies. Whether they are 315 or 688, the result is the same : you have Hashi's. Antibodies fluctuate, but once you have them, you have them for life - well, the life of your thyroid, anyway. Could be that they've been even higher in between, but you wouldn't have known about it, because you didn't test. The fact that they are higher now than they were, doesn't mean you're getting worse.
In any case, there is nothing doctors can or will do about antibodies. They don't even understand them. But, you can try and lower them by taking selenium - which also helps with conversion, so a good thing to take. And, you can try a 100% gluten-free diet, which also lowers antibodies, and often makes people feel much better. And, don't let your endo try and raise your TSH! It's perfect as it is.