Who can perform Hajj? All of the pillars of Islam are built upon mercy and love. Allah obliges upon us things that are better for us and will make us better people.
When we look at all of these pillars we see that there are exceptions to the general rule. The general rule is sane, mature Muslims. If you are physically well and can financially afford to perform Hajj, then you are OK to go. However, if you are not physically OK or have financially difficulties then you are exempt.
If you are in debt then you should go to the person who you have lent money from and ask them if you can perform Hajj. If they say no, then you have to pay the money back before you make Hajj. That money is their right first and foremost.