Start by getting more information about the policy.
If you haven't already, find out:
If you really only have the summer semester to increase your GPA, or if it's fall. Often some university policies include summer when referring to "semesters" and others may not.
If there are any summer courses at all that you can take, whether or not they seem relevant to your degree. It may make a difference whether they count toward your formal graduation requirements.
If it is possible to petition for an exception. Most universities have a process like this. Find out how the process works at your university, who makes the decisions, and what kind of evidence or arguments you can include. Pay close attention to the details of the process, including specific forms, deadlines, etc, as missing a detail could lead your petition to be denied.
Your faculty advisor may not be the best person to ask about this; individual faculty aren't necessarily familiar with these processes. Try someone like a department chair or graduate chair / coordinator who is more involved with the administration of the graduate program.
If it really turns out that you cannot do anything to stay in the program:
Well, start making plans for what you will do with your life instead of graduate school. There are lots of possibilities.
Since you mention that you are an international student, this would likely also mean that you will have to return to your home country, since your student visa would become invalid. Check with your university's international office to find out more about this process, and the relevant deadlines. You may find that you have to leave within a short period of time after ending your studies, possibly just a few days. If you can't or are unwilling to return to your home country for any reason, you will probably need to consult an immigration lawyer.
It would be worth finding out if you can voluntarily withdraw from the university instead of being dismissed. This might help your transcript look better if you decide to pursue graduate study again in the future.
My research also isn't going well, my lab mates are very unsupportive and always try to put me down.
Well, if you're not staying in the program, then this is moot. If you do stay, then this is a separate issue to address. We have lots of other questions here about similar situations, but for instance you could find ways to work more independently from these students, or switch to another lab.
I feel like a failure since I had no problem in academic or research a few years back.
Just because you may not succeed at one particular pursuit, does not mean that you are a failure as a person! It is normal to be frustrated and disappointed, but if these feelings are severe or interfere with your life, talk to your university's counseling service.
