Short answer: Probably not, no. And you certanily wouldn't be better off.
As a general rule of life, where there is a future, there is hope. And that thing you really want but can't have sounds better than it is.
Also, you (like me actually) are nearing a transition stage in your life where you have to enter the proper adult world. I have friends who left uni over a year ago, and sure some of them took a while to find a job relevant job, but they all did eventually (science and arts students); and none of us are geniuses, just persistent. It's pretty common when nothing's very certain to think 'shit.. CAN I do this?' If youv'e made it this far, you probably can. Even if you can't there will be something else you will find you can do. Make a list of skills and areas of study you know you're strong at; and don't be too modest. If anything, be a little bit arrogant, since you'll get better with further challenge at your lesser strengths.
With regards to intelligence, people only let others know about the things they did well. Everyone sweeps their silly mistakes under the carpet. I doubt many people in you seminars really make less mistakes than you do if they actually try to push themselves.
Looks wise, I'm assuming you're worried about women not finding you attractive? Most people can be made to look at least reasonably attractive just with clean, fitting clothes; good hygiene; a well chosen haircut; good deodrant/ cologne; a decent exercise routine (not necessarily 'ripped') and a dose of confident body language. Factor in that beauty is subjective and consider that these following men are said to be attractive by women: Johnny Depp, David Tennant, Daniel Craig; yet have nothing in common with each other looks-wise; theres a fair chance you could be pretty darn attractive to a sizeable group of women. If there's something specific bothering you (maybe acne, dandruff or a body odour issue) make an appointment with your GP asap and just keep trying them til you find the treatment that works.
Since social skills are skills, they can be developed. Therefore I recommend two things: joining a sports club which will make you fitter and stronger whilst allowing you some light socialising to help make you more comfortable in social situations; which should overall boost your confidence Secondly, dedicate as much spare time as possible to more activities that make you feel confident. It should be like you're making one (or maybe more) small steps of progress everyday. For me, I go to judo 3 times a week, I workout at home and I play guitar. So pretty much every day I make some small accomplishment, even if overall the day went terrible. At the very least, at the end of most days I know i've either got a little better at a throw or ground technique, or performed well in one randori match; gained a few beats per min of speed on a lick or learnt something new on guitar; or managed to do a few more reps than I could the previous time when using my exercise equipment. Generally, even if I get a hard knockback from something or other, those things help me bounce back at least partially; and that helps me maintain confidence.
Also, with jobs and things, try to make a list of manageable tasks for the day even just 'go see the careers advisor, book a meeting and collect leaflets'. or 'do one application form for a job'. This will do your general organisation a favour and remind you that you're making steps towards positive progress.
Also, I'm getting the impression some people you socialise with put you down a lot. Ditch them. Make the most of activity clubs in uni to meet more people who like the same things you do and treat you decently, cos it isn't reasonable to be rude to someone just because they're shy or quiet. Also (kinda obvious, but) try to take care in who you confide personal things to, and if you know someone who always gossips about their other friends, keep their noses out of your business.
Try to take the steps I've outlined above to build your confidence; but if you can, sooner rather than later try to stand up for yourself. In my experience the best way to do this is:
1) Act like their comment hasn't actually upset you, but has left you a little bemused and surprised.
2) Take an opportunity to highlight the hypocracy in the comment in a light hearted manner (most insults I've had from people in my time have been them projecting their inadequacies onto me, so this is usually pretty easy). Or else, calmly make it clear that you're surprised the issue in question is so important to them, and imply you think their attitude is a little childish. Again a fairly light hearted response usually helps here.
Example: I was chatting with a couple of girls in the student bar with a former housemate. He obviously saw me as a threat so tried to emasculate me by saying that I sometimes use an apricot scrub thingy to wash my face and imply it was effeminate. My reply was "Yeah! It's called making an effort (light laughter)!. And anyway, I find that a little rich comming from a guy who walks around campus wearing a headband designed to hold women's hair off their face when they remove their makeup; who genuinely thinks it looks cool!" I won, they didn't care if I used a skin product more commonly used by women, since I didn't; and winning is awesome
Hope this helps. Just keep setting yourself specific days and times to start any goal you want to accomplish and you'll make steady progress.
