Then the judge said he knew I contested but since my attorney didn't
file a motion to terminate or change guardianship he had no choice but
to give my aunt guardianship.
I am a single mom who just paid $1,500 and I'm broke.
It sounds like your attorney screwed up. This is not too surprising, as a contest of a guardianship would normally cost $6,000 to $18,000 to litigate a dispute like this properly, although that is no excuse for doing a poor job by making a mistake in failing to file the right legal forms. (A fee of $1,500 would be about right for an uncontested petition to change your own name, a much simpler case.)
(It is also, realistically, not cost effective to sue for malpractice, although you might grieve the lawyer with the bar association even though that will not provide you personally with any relief.)
Can I file these motions or petitions myself? What is the next step to
take and is there anything online that gives me any idea how to take
those steps?
While you can, it verges on futile at this point, especially if you try to do it yourself.
In the initial hearing, you might have been on something approaching a level playing field. Now, to prevail, you are very likely going to have to show that the aunt did something really horrible at sometime after the most recent hearing.
Your lawyer screwed up and in all likelihood you will not be able to overcome that screw up without the assistance of a lawyer specializing in protective proceedings, if it is possible at all. If this happened very recently (e.g. the last 14 days) it may be possible to correct the mistake with a motion to reconsider, but it will take a lawyer for you to have a prayer of success. But, a judge is very unlikely to reconsider the case after so recently denying you relief without some case law exactly on point and an argument carefully tailored to that particular judge, even if that denial was due to a screw up by your lawyer. Since you can't afford that, you are basically stuck.